A survivor reacts as he attends a wreath-laying ceremony at the "death wall" at the former Nazi German concentration and extermination camp Auschwitz, 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 TPX IMAGES OF THE DAY 

Poland's President Andrzej Duda, museum director Piotr Cywinski and survivors arrive at the former Nazi German concentration and extermination camp Auschwitz to attend ceremonies marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Survivors and other guests arrive to attend a wreath-laying ceremony at the "death wall" at the former Nazi German concentration and extermination camp Auschwitz, 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 

A survivor reacts at the former Nazi German concentration and extermination camp Auschwitz, during a ceremony marking the 75th anniversary of the liberation of the camp and International Holocaust Victims Remembrance Day, in Oswiecim, Poland, January 27, 2020. REUTERS/Kacper Pempel 

Survivors carry a wreath as they arrive to attend a wreath-laying ceremony at the "death wall" at the former Nazi German concentration and extermination camp Auschwitz, 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 

A survivor attends a wreath-laying ceremony at the "death wall" at the former Nazi German concentration and extermination camp Auschwitz, 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 

Wreaths and flowers are seen after a wreath-laying ceremony at the "death wall" at the former Nazi German concentration and extermination camp Auschwitz, 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 

Survivor Igor Malicki arrives to attend a wreath-laying ceremony at the "death wall" at the former Nazi German concentration and extermination camp Auschwitz, 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 

A survivor attends a wreath-laying ceremony at the "death wall" at the former Nazi German concentration and extermination camp Auschwitz, 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 

Survivors carry a wreath as they arrive to attend a wreath-laying ceremony at the "death wall" at the former Nazi German concentration and extermination camp Auschwitz, 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 

Jona Laks, survivor of Nazi Dr. Josef Mengele's experiments and her granddaughter, Lee Aldar walk as they visit the Auschwitz death camp, in Oswiecim, Poland January 26, 2020 REUTERS/Nir Elias TPX IMAGES OF THE DAY 

Jona Laks, survivor of Dr. Josef Mengele's twins experimentsand her granddaughter, Lee Aldar stand next to the gate with the slogan "Arbeit macht frei" ("Work sets you free") as they start their visit at the Auschwitz death camp in Oswiecim, Poland January 26, 2020 REUTERS/Nir Elias 

Jona Laks, survivor of Dr. Josef Mengele's twins experiments and her granddaughter, Lee Aldar hug in front of the block number 10 which served as Mengele's laboratory, as they visit the Auschwitz death camp in Oswiecim, Poland January 26, 2020 REUTERS/Nir Elias 

A survivor attends a wreath-laying ceremony at the "death wall" at the former Nazi German concentration and extermination camp Auschwitz, 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 Edith Notowicz, 90, attends a ceremony 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 

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 

A frozen rose is seen next to the word 'Auschwitz' at the Gleis 17 (Platform 17) memorial, a platform at Berlin-Grunewald train station from where some 50,000 Jewish citizens were deported by train to the Nazi concentration camps between 1941 and 1945, in Berlin, Germany, January 24, 2020. Picture taken with a fish-eye lens. REUTERS/Fabrizio Bensch TPX IMAGES OF THE DAY 

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 

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 

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 

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 

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 

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 

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 

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 

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 

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 

Israeli Prime Minister Benjamin Netanyahu and Israeli President Reuven Rivlin pose with world leaders for a group photo during the Fifth World Holocaust Forum at the Yad Vashem Holocaust memorial museum in Jerusalem, January 23, 2020. Abir Sultan/Pool via REUTERS 

French President Emmanuel Macron takes part in a wreath-laying ceremony at the World Holocaust Forum marking 75 years since the liberation of the Nazi extermination camp Auschwitz, at Yad Vashem Holocaust memorial centre in Jerusalem January 23, 2020. REUTERS/Ronen Zvulun/Pool 

Britain's Prince Charles lays a wreath during the Fifth World Holocaust Forum at the Yad Vashem Holocaust memorial museum in Jerusalem, January 23, 2020. Abir Sultan/Pool via REUTERS 

Attendees during the Fifth World Holocaust Forum at the Yad Vashem Holocaust memorial museum in Jerusalem, January 23, 2020. Abir Sultan/Pool via REUTERS 

Rabbi Israel Meir Lau Chairman of the Yad Vashem Council speaks to Israeli Prime Minister Benjamin Netanyahu and Russian President Vladimir Putin at the World Holocaust Forum marking 75 years since the liberation of the Nazi extermination camp Auschwitz, at Yad Vashem Holocaust memorial centre in Jerusalem January 23, 2020. REUTERS/Ronen Zvulun/Pool 

German President Frank-Walter Steinmeier and French President Emmanuel Macron hug at the World Holocaust Forum marking 75 years since the liberation of the Nazi extermination camp Auschwitz, at Yad Vashem Holocaust memorial centre in Jerusalem January 23, 2020. REUTERS/Ronen Zvulun/Pool 

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 

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 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 

An aerial picture showes barracks and buildings of former Nazi German Auschwitz I concentration camp complex in Oswiecim, Poland, January 14, 2020. REUTERS/Axel Schmidt 

The watchtowers of former Nazi German Auschwitz-Birkenau concentration camp complex are pictured in Oswiecim, Poland, January 14, 2020. Picture taken January 14, 2020. REUTERS/Axel Schmidt 

Shoes of prisoners are seen in the former Nazi German Auschwitz concentration camp complex in Oswiecim, Poland, January 15, 2020. Picture taken January 15, 2020. REUTERS/Axel Schmidt 

An aerial picture showes barracks and buildings of former Nazi German Auschwitz I concentration camp complex in Oswiecim, Poland, January 14, 2020. REUTERS/Axel Schmidt 

A crematorium furnace is seen at former Nazi German Auschwitz concentration camp complex in Oswiecim, Poland January 15, 2020. Picture taken January 15, 2020. REUTERS/Axel Schmidt 

An aerial picture showe barracks and buildings of former Nazi German Auschwitz-Birkenau concentration camp complex in Oswiecim, Poland, January 15, 2020. Picture taken with a drone January 15, 2020. REUTERS/Axel Schmidt 

Suitcases of prisoners are seen in the former Nazi German Auschwitz concentration camp complex in Oswiecim, Poland, January 15, 2020. Picture taken January 15, 2020. REUTERS/Axel Schmidt 

A gallows is seen at the Nazi German Auschwitz concentration camp complex in Oswiecim, Poland, January 15, 2020. Picture taken January 15, 2020. REUTERS/Axel Schmidt 

An aerial picture showe barracks and buildings of former Nazi German Auschwitz-Birkenau concentration camp complex in Oswiecim, Poland, January 15, 2020. Picture taken with a drone January 15, 2020. REUTERS/Axel Schmidt 

An aerial picture showe barracks and buildings of former Nazi German Auschwitz-Birkenau concentration camp complex in Oswiecim, Poland, January 15, 2020. Picture taken with a drone January 15, 2020. REUTERS/Axel Schmidt 

The buildings of former Nazi German Auschwitz concentration camp complex are seen in Oswiecim, Poland, January 15, 2020. Picture taken January 15, 2020. REUTERS/Axel Schmidt 

An aerial picture showe barracks and buildings of former Nazi German Auschwitz-Birkenau concentration camp complex in Oswiecim, Poland, January 15, 2020. Picture taken with a drone January 15, 2020. REUTERS/Axel Schmidt 

An aerial picture showe barracks and buildings of former Nazi German Auschwitz-Birkenau concentration camp complex in Oswiecim, Poland, January 15, 2020. Picture taken with a drone January 15, 2020. REUTERS/Axel Schmidt