The site of the former Nazi German concentration and extermination camp Auschwitz is pictured during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Nora Savosnick 

The site of the former Nazi German concentration and extermination camp Auschwitz is pictured during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Nora Savosnick 

The site of the former Nazi German concentration and extermination camp Auschwitz is pictured during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Nora Savosnick 

Poland's President Andrzej Duda and his wife Agata Kornhauser-Duda light a candle at the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Poland's first lady Agata Kornhauser-Duda talks with Holocaust survivor Marian Turski next to Czech Republic's Prime Minister Andrej Babis, Queen Mathilde of Belgium, King Willem-Alexander of the Netherlands and King Felipe of Spain at the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Mayor of London Sadiq Khan lights a candle at the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Poland's President Andrzej Duda and his wife Agata Kornhauser-Duda light a candle at the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

German President Frank-Walter Steinmeier and his wife Elke Buedenbender walk next to the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

German President Frank-Walter Steinmeier and his wife Elke Buedenbender stand next to the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

German President Frank-Walter Steinmeier and his wife Elke Buedenbender walk next to the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

German President Frank-Walter Steinmeier and his wife Elke Buedenbender stand next to the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Poland's President Andrzej Duda and his wife Agata Kornhauser-Duda, Holocaust survivor Marian Turski, King Philippe of Belgium, King Felipe of Spain walk with candles to light them at the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Sweden's Crown Princess Victoria lights a candle at the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Poland's President Andrzej Duda and his wife Agata Kornhauser-Duda light a candle at the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Sweden's Crown Princess Victoria lights a candle at the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Britain's Camilla, Duchess of Cornwall, is seen near the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Britain's Camilla, Duchess of Cornwall, and Mayor of London Sadiq Khan light candles at the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Britain's Camilla, Duchess of Cornwall, looks on at the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

German President Frank-Walter Steinmeier and his wife Elke Buedenbender look at the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Britain's Camilla, Duchess of Cornwall, lights a candle at the Monument to the Victims at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

A watch tower is illuminated at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

A watch tower is illuminated at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

A watch tower is illuminated at the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Survivors attend the official ceremony marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

A sentry box is pictured on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Guests listen as Auschwitz survivor Stanislaw Zalewski, President of the Polish Union of Former Political Prisoners of Nazi Prisons and Concentration Camps, delivers a speech during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Heads of states and guests listen as Auschwitz survivor Stanislaw Zalewski, President of the Polish Union of Former Political Prisoners of Nazi Prisons and Concentration Camps, delivers a speech during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Heads of states listen as Ronald S. Lauder, representative of "The Pillars of Remembrance", delivers a speech during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Heads of states listen as Auschwitz survivor Stanislaw Zalewski, President of the Polish Union of Former Political Prisoners of Nazi Prisons and Concentration Camps, delivers a speech during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Auschwitz survivor Stanislaw Zalewski, President of the Polish Union of Former Political Prisoners of Nazi Prisons and Concentration Camps, delivers a speech during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Ronald S. Lauder, representative of "The Pillars of Remembrance", delivers a speech during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

The sun sets over the former Nazi German concentration and extermination camp Auschwitz II-Birkenau, during ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Holocaust survivor Marian Turski delivers a speech during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

People attend the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

People attend the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Holocaust survivor Marian Turski delivers a speech during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

A survivor reacts during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

King Felipe of Spain and his wife Queen Letizia, King Willem-Alexander and Queen Maxima of the Netherlands, Poland's President Andrzej Duda, wife Agata Kornhauser-Duda and King Philippe of Belgium attend the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Holocaust survivor Bat-Sheva Dagan delivers a speech during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Poland's President Andrzej Duda delivers a speech during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Israeli President Reuven Rivlin, German President Frank-Walter Steinmeier and his wife Elke Buedenbender attend the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Poland's President Andrzej Duda delivers a speech during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Poland's President Andrzej Duda delivers a speech during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Britain's Camilla, King Willem-Alexander and Queen Maxima of the Netherlands attend the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

New York Governor Andrew M. Cuomo gestures ahead of ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Mayor of London Sadiq Khan speaks with Jozef Wanger, member of the Auschwitz-Birkenau Foundation, ahead of ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Mayor of London Sadiq Khan and Jozef Wanger, member of the Auschwitz-Birkenau Foundation, are pictured ahead of ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day on the site of the former Nazi German concentration and extermination camp Auschwitz II-Birkenau in Brzezinka near Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Mayor of London Sadiq Khan attends the ceremony of unveiling a plaque informing about financial support of London to the Auschwitz-Birkenau Foundation during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Mayor of London Sadiq Khan attends the ceremony of unveiling a plaque informing about financial support of London to the Auschwitz-Birkenau Foundation during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Mayor of London Sadiq Khan attends the ceremony of unveiling a plaque informing about financial support of London to the Auschwitz-Birkenau Foundation during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Mayor of London Sadiq Khan and Holocaust survivor Renee Salt arrive to attend the ceremony of unveiling a plaque informing about financial support of London to the Auschwitz-Birkenau Foundation during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Mayor of London Sadiq Khan and Holocaust survivor Renee Salt arrive to attend the ceremony of unveiling a plaque informing about financial support of London to the Auschwitz-Birkenau Foundation during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Holocaust survivor Renee Salt arrives with Mayor of London Sadiq Khan to attend the ceremony of unveiling a plaque informing about financial support of London to the Auschwitz-Birkenau Foundation during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Mayor of London Sadiq Khan and Director of the Auschwitz-Birkenau State Museum Piotr Cywinski attend the ceremony of unveiling a plaque informing about financial support of London to the Auschwitz-Birkenau Foundation during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Mayor of London Sadiq Khan holds the hand of Holocaust survivor Renee Salt as they arrive to attend the ceremony of unveiling a plaque informing about financial support of London to the Auschwitz-Birkenau Foundation during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Mayor of London Sadiq Khan and Holocaust survivor Renee Salt arrive to attend the ceremony of unveiling a plaque informing about financial support of London to the Auschwitz-Birkenau Foundation during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Mayor of London Sadiq Khan and Holocaust survivor Renee Salt arrive to attend the ceremony of unveiling a plaque informing about financial support of London to the Auschwitz-Birkenau Foundation during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Mayor of London Sadiq Khan and Holocaust survivor Renee Salt arrive to attend the ceremony of unveiling a plaque informing about financial support of London to the Auschwitz-Birkenau Foundation during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Mayor of London Sadiq Khan and Director of the Auschwitz-Birkenau State Museum Piotr Cywinski attend the ceremony of unveiling a plaque informing about financial support of London to the Auschwitz-Birkenau Foundation during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel 

Mayor of London Sadiq Khan attends the ceremony of unveiling a plaque informing about financial support of London to the Auschwitz-Birkenau Foundation during the ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Aleksandra Szmigiel