Police officers secure the area where an attacker stabbed a female police administrative worker, in Rambouillet, near Paris, France, April 23, 2021. REUTERS/Gonzalo Fuentes

A police officer stands guard in the area where an attacker stabbed a female police administrative worker, in Rambouillet, near Paris, France, April 23, 2021. REUTERS/Gonzalo Fuentes

Tennis - ATP 500 - Barcelona Open - Real Club de Tennis Barcelona, Barcelona, Spain - April 23, 2021 Spain’s Rafael Nadal in action during his quarter final match against Great Britain’s Cameron Norrie REUTERS/Albert Gea

Tennis - ATP 500 - Barcelona Open - Real Club de Tennis Barcelona, Barcelona, Spain - April 23, 2021 Spain’s Rafael Nadal in action during his quarter final match against Great Britain’s Cameron Norrie REUTERS/Albert Gea

Pfizer CEO Albert Bourla talks during a press conference with European Commission President Ursula von der Leyen after a visit to oversee the production of the Pfizer-BioNtech COVID-19 vaccine at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Police officers secure the area where an attacker stabbed a female police administrative worker, in Rambouillet, near Paris, France, April 23, 2021. REUTERS/Gonzalo Fuentes

Pfizer CEO Albert Bourla talks during a press conference with European Commission President Ursula von der Leyen after a visit to oversee the production of the Pfizer-BioNtech COVID-19 vaccine at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Pfizer CEO Albert Bourla talks during a press conference with European Commission President Ursula von der Leyen after a visit to oversee the production of the Pfizer-BioNtech COVID-19 vaccine at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Pfizer CEO Albert Bourla talks during a press conference with European Commission President Ursula von der Leyen after a visit to oversee the production of the Pfizer-BioNtech COVID-19 vaccine at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Pfizer CEO Albert Bourla talks during a press conference with European Commission President Ursula von der Leyen after a visit to oversee the production of the Pfizer-BioNtech COVID-19 vaccine at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Police officers secure the area where an attacker stabbed a female police administrative worker, in Rambouillet, near Paris, France, April 23, 2021. REUTERS/Gonzalo Fuentes

European Commission President Ursula von der Leyen addresses a press conference after a visit to oversee the production of the Pfizer-BioNtech COVID-19 vaccine at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

European Commission President Ursula von der Leyen addresses a press conference after a visit to oversee the production of the Pfizer-BioNtech COVID-19 vaccine at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Tennis - ATP 500 - Barcelona Open - Real Club de Tennis Barcelona, Barcelona, Spain - April 23, 2021 Great Britain’s Cameron Norrie in action during his quarter final match against Spain’s Rafael Nadal REUTERS/Albert Gea

European Commission President Ursula von der Leyen addresses a press conference after a visit to oversee the production of the Pfizer-BioNtech COVID-19 vaccine at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Police officers secure the area where an attacker stabbed a female police administrative worker, in Rambouillet, near Paris, France, April 23, 2021. REUTERS/Gonzalo Fuentes

European Commission President Ursula von der Leyen addresses a press conference after a visit to oversee the production of the Pfizer-BioNtech COVID-19 vaccine at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

European Commission President Ursula von der Leyen addresses a press conference after a visit to oversee the production of the Pfizer-BioNtech COVID-19 vaccine at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

European Commission President Ursula von der Leyen addresses a press conference after a visit to oversee the production of the Pfizer-BioNtech COVID-19 vaccine at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

European Commission President Ursula von der Leyen addresses a press conference after a visit to oversee the production of the Pfizer-BioNtech COVID-19 vaccine at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Police officers secure the area where an attacker stabbed a female police administrative worker, in Rambouillet, near Paris, France, April 23, 2021. REUTERS/Gonzalo Fuentes

Television presenter Christian Jessen arrives at a court in relation to a defamation case Northern Ireland First Minister Arlene Foster has brought against him, in Belfast, Northern Ireland April 23, 2021. REUTERS/Jason Cairnduff

Television presenter Christian Jessen arrives at a court in relation to a defamation case Northern Ireland First Minister Arlene Foster has brought against him, in Belfast, Northern Ireland April 23, 2021. REUTERS/Jason Cairnduff

Police officers secure the area where an attacker stabbed a female police administrative worker, in Rambouillet, near Paris, France, April 23, 2021. REUTERS/Gonzalo Fuentes

U.S. Special Presidential Envoy for Climate John Kerry greets Transportation Secretary Pete Buttigieg, not pictured, ahead of a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

World leaders appear on a video screen during a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

U.S. Special Presidential Envoy for Climate John Kerry looks on during a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

U.S. Transportation Secretary Buttigieg looks on during a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden walks to the podium ahead of a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden walks to the podium ahead of a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden walks to the podium ahead of a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

World leaders appear on a video screen during a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden looks on between Transportation Secretary Pete Buttigieg, left, and United States Trade Representative Katherine Tai, right, during a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

U.S. Transportation Secretary Buttigieg looks on during a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden looks on after delivering opening remarks during a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

Television presenter Christian Jessen arrives at a court in relation to a defamation case Northern Ireland First Minister Arlene Foster has brought against him, in Belfast, Northern Ireland April 23, 2021. REUTERS/Jason Cairnduff

Television presenter Christian Jessen arrives at a court in relation to a defamation case Northern Ireland First Minister Arlene Foster has brought against him, in Belfast, Northern Ireland April 23, 2021. REUTERS/Jason Cairnduff

Television presenter Christian Jessen arrives at a court in relation to a defamation case Northern Ireland First Minister Arlene Foster has brought against him, in Belfast, Northern Ireland April 23, 2021. REUTERS/Jason Cairnduff

Television presenter Christian Jessen arrives at a court in relation to a defamation case Northern Ireland First Minister Arlene Foster has brought against him, in Belfast, Northern Ireland April 23, 2021. REUTERS/Jason Cairnduff

Television presenter Christian Jessen arrives at a court in relation to a defamation case Northern Ireland First Minister Arlene Foster has brought against him, in Belfast, Northern Ireland April 23, 2021. REUTERS/Jason Cairnduff

Gymnastics - 2021 European Artistic Gymnastics Championships - St. Jakobshalle, Basel, Switzerland - April 23, 2021 Germany's Elisabeth Seitz in action during the women's floor REUTERS/Arnd Wiegmann

Gymnastics - 2021 European Artistic Gymnastics Championships - St. Jakobshalle, Basel, Switzerland - April 23, 2021 Germany's Elisabeth Seitz in action during the women's floor REUTERS/Arnd Wiegmann

European Commission President Ursula von der Leyen sticks an EU flag label during a visit at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Tennis - WTA 500 - Stuttgart Open - Porsche-Arena, Stuttgart, Germany - April 23, 2021 Australia's Ashleigh Barty reacts during her quarter final match against Czech Republic’s Karolina Pliskova Pool via REUTERS/Marijan Murat

European Commission President Ursula von der Leyen sticks an EU flag label during a visit at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Television presenter Christian Jessen arrives at a court in relation to a defamation case Northern Ireland First Minister Arlene Foster has brought against him, in Belfast, Northern Ireland April 23, 2021. REUTERS/Jason Cairnduff

Tennis - WTA 500 - Stuttgart Open - Porsche-Arena, Stuttgart, Germany - April 23, 2021 Australia's Ashleigh Barty in action during her quarter final match against Czech Republic’s Karolina Pliskova Pool via REUTERS/Marijan Murat

Gymnastics - 2021 European Artistic Gymnastics Championships - St. Jakobshalle, Basel, Switzerland - April 23, 2021 Third place Great Britain's Jessica Gadirova celebrates on the podium with her bronze medal during the award ceremony of the Women's overall final REUTERS/Arnd Wiegmann

European Commission President Ursula von der Leyen and Belgium's Prime Minister Alexander De Croo watch a worker during a visit at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Gymnastics - 2021 European Artistic Gymnastics Championships - St. Jakobshalle, Basel, Switzerland - April 23, 2021 Second placed Russia's Angelina Melnikova celebrates on the podium with her silver medal during the award ceremony of the Women's overall final REUTERS/Arnd Wiegmann

European Commission President Ursula von der Leyen, Pfizer CEO Albert Bourla and Belgium's Prime Minister Alexander De Croo watch workers moving boxes of vaccines from a freezer during a visit at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Gymnastics - 2021 European Artistic Gymnastics Championships - St. Jakobshalle, Basel, Switzerland - April 23, 2021 First placed Russia's Viktoriia Listunova celebrates on the podium during the award ceremony of the Women's overall final REUTERS/Arnd Wiegmann

Gymnastics - 2021 European Artistic Gymnastics Championships - St. Jakobshalle, Basel, Switzerland - April 23, 2021 First placed Russia's Viktoriia Listunova celebrates on the podium with her gold medal during the award ceremony of the Women's overall final REUTERS/Arnd Wiegmann

Gymnastics - 2021 European Artistic Gymnastics Championships - St. Jakobshalle, Basel, Switzerland - April 23, 2021 Second placed Russia's Angelina Melnikova, first placed Russia's Viktoriia Listunova and third placed Britain's Jessica Gadirova celebrate on the podium during the award ceremony of the Women's overall final REUTERS/Arnd Wiegmann

Gymnastics - 2021 European Artistic Gymnastics Championships - St. Jakobshalle, Basel, Switzerland - April 23, 2021 Second placed Russia's Angelina Melnikova, first placed Russia's Viktoriia Listunova and third placed Britain's Jessica Gadirova celebrate on the podium during the award ceremony of the Women's overall final REUTERS/Arnd Wiegmann

U.S. President Joe Biden delivers remarks in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden removes his face mask before delivering remarks in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden looks on following his remarks in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden delivers remarks in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 23, 2021. REUTERS/Tom Brenner

An aerial view of the River Nile valley pictured through the window of an airplane on a flight between Cairo and Luxor, Egypt April 11, 2021. Picture taken April 11, 2021. REUTERS/Amr Abdallah Dalsh