View of the town of Halki, amid the coronavirus disease (COVID-19) pandemic, on the island of Halki, Greece, April 13, 2021. Picture taken April 13, 2021. Picture taken with a drone. REUTERS/Vassilis Triandafyllou

U.S. Vice President Kamala Harris participates in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 22, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden walks towards a podium before participating in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 22, 2021. REUTERS/Tom Brenner

World leaders appear on screen during a virtual Climate Summit, seen from the East Room at the White House in Washington, U.S., April 22, 2021. REUTERS/Tom Brenner

U.S. Vice President Kamala Harris is reflected in a tablet screen while participating in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 22, 2021. REUTERS/Tom Brenner

John Kerry, Special Presidential Envoy for Climate, looks up at a video screen while participating in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 22, 2021. REUTERS/Tom Brenner

John Kerry, Special Presidential Envoy for Climate, looks up at a video screen while participating in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 22, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden puts his protective face mask 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 22, 2021. REUTERS/Tom Brenner

U.S. Vice President Kamala Harris participates in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 22, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden participates in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 22, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden participates in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 22, 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 22, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden participates in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 22, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden participates in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 22, 2021. REUTERS/Tom Brenner

U.S. President Joe Biden takes his face mask off before delivering remarks in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 22, 2021. REUTERS/Tom Brenner

Medical workers stand near medical materials at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

Patients suffering from the coronavirus disease (COVID-19) lay in beds at the Stark Arena sports venue that is turned into a COVID hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

U.S. Vice President Kamala Harris participates in a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 22, 2021. REUTERS/Tom Brenner

Iraqi woman swimming trainer Elaf, 35, teaches a child how to swim and dive, amid the outbreak of the coronavirus disease (COVID-19), at a swimming pool in Basra, Iraq, April 22, 2021. REUTERS/Essam al-Sudani

A patient suffering from the coronavirus disease (COVID-19) uses his phone at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

Patients suffering from the coronavirus disease (COVID-19) lay in beds at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

Patients suffering from the coronavirus disease (COVID-19) lay in beds at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

Patients suffering from the coronavirus disease (COVID-19) lay in beds at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

A patient suffering from the coronavirus disease (COVID-19) talks on a phone at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

Patients suffering from the coronavirus disease (COVID-19) lay in beds at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

Patients suffering from the coronavirus disease (COVID-19) lay in beds at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

Patients suffering from the coronavirus disease (COVID-19) lay in beds at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

Patients suffering from the coronavirus disease (COVID-19) lay in beds at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

U.S. Vice President Kamala Harris is seen on the screen as Mexico's President Andres Manuel Lopez Obrador attends a virtual U.S. global climate summit, at the National Palace in Mexico City, Mexico, April 22, 2021. REUTERS/Henry Romero

Medical workers treat patients suffering from the coronavirus disease (COVID-19) at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

Medical workers treat patients suffering from the coronavirus disease (COVID-19) at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

Messages of gratitude from patients to medical workers are seen on a wall at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

Medical workers treat patients suffering from the coronavirus disease (COVID-19) at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

U.S. Vice President Kamala Harris is seen on the screen as Mexico's President Andres Manuel Lopez Obrador attends a virtual U.S. global climate summit, at the National Palace in Mexico City, Mexico, April 22, 2021. REUTERS/Henry Romero

Medical workers treat patients suffering from the coronavirus disease (COVID-19) at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

A medical worker treats patients suffering from the coronavirus disease (COVID-19) at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

A note reading "Thank you" is seen on a wall as medical workers treat patients suffering from the coronavirus disease (COVID-19) at the Stark Arena sports venue that is turned into a COVID-19 hospital in Belgrade, Serbia, April 22, 2021. REUTERS/Marko Djurica

U.S. President Joe Biden and Vice President Kamala Harris walk on stage for a virtual Climate Summit with world leaders in the East Room at the White House in Washington, U.S., April 22, 2021. REUTERS/Tom Brenner

Special Presidential Envoy for Climate John Kerry looks on as 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 22, 2021. REUTERS/Tom Brenner

A man wearing a protective mask walks through an alley of souvenir shops at a tourist market, amid the coronavirus disease (COVID-19) pandemic in Luxor, Egypt April 9, 2021. Picture taken April 9, 2021. REUTERS/Amr Abdallah Dalsh

A shopkeeper waits for customers in an alley of souvenir shops at a tourist market, amid the coronavirus disease (COVID-19) pandemic in Luxor, Egypt April 9, 2021. Picture taken April 9, 2021. REUTERS/Amr Abdallah Dalsh

Vendors wait for customers in an alley of souvenir shops at a tourist market, amid the coronavirus disease (COVID-19) pandemic in Luxor, Egypt April 9, 2021. Picture taken April 9, 2021. REUTERS/Amr Abdallah Dalsh

Tennis - WTA 500 - Stuttgart Open - Porsche-Arena, Stuttgart, Germany - April 22, 2021 Germany's Anna-Lena Friedsam in action during her round of 16 match against Belarus' Aryna Sabalenka Pool via REUTERS/Thomas Kienzle

Gymnastics - 2021 European Artistic Gymnastics Championships - St. Jakobshalle, Basel, Switzerland - April 22, 2021 Austria's Vinzenz Hock in action during the Men's Rings REUTERS/Arnd Wiegmann

Mexico's President Andres Manuel Lopez Obrador attends a virtual U.S. global climate summit, at the National Palace in Mexico City, Mexico, April 22, 2021. REUTERS/Henry Romero

First Minister Nicola Sturgeon, leader of the Scottish National Party (SNP), drinks a coffee during a campaign for the Scottish parliamentary election in Victoria Road, Glasgow, Scotland, Britain April 22, 2021. Jane Barlow/Pool via REUTERS

First Minister Nicola Sturgeon, leader of the Scottish National Party (SNP), talks during a campaign for the Scottish parliamentary election in Victoria Road, Glasgow, Scotland, Britain April 22, 2021. Jane Barlow/Pool via REUTERS

First Minister Nicola Sturgeon, leader of the Scottish National Party (SNP), speaks with a member of the public during a campaign for the Scottish parliamentary election in Victoria Road, Glasgow, Scotland, Britain April 22, 2021. Jane Barlow/Pool via REUTERS

First Minister Nicola Sturgeon, leader of the Scottish National Party (SNP), drinks a coffee during a campaign for the Scottish parliamentary election in Victoria Road, Glasgow, Scotland, Britain April 22, 2021. Jane Barlow/Pool via REUTERS

Climbing - IFSC Climbing World Cup - Climbing Center Haslital, Meiringen, Switzerland - April 16, 2021 Spain’s Alberto Gines Lopez during the men's qualifications REUTERS/Denis Balibouse

Climbing - IFSC Climbing World Cup - Climbing Center Haslital, Meiringen, Switzerland - April 16, 2021 Italy’s Ludovico Fossali during the men's qualifications REUTERS/Denis Balibouse

Climbing - IFSC Climbing World Cup - Climbing Center Haslital, Meiringen, Switzerland - April 16, 2021 Kazakhstan’s Rishat Khaibullin during the men's qualifications REUTERS/Denis Balibouse

Climbing - IFSC Climbing World Cup - Climbing Center Haslital, Meiringen, Switzerland - April 16, 2021 Austria’s Jakob Schubert during the men's qualifications REUTERS/Denis Balibouse

Climbing - IFSC Climbing World Cup - Climbing Center Haslital, Meiringen, Switzerland - April 16, 2021 Japan’s Miho Nonaka during the women's qualifications REUTERS/Denis Balibouse

Climbing - IFSC Climbing World Cup - Climbing Center Haslital, Meiringen, Switzerland - April 16, 2021 Czech Republic's Adam Ondra during the men's qualifications REUTERS/Denis Balibouse

Climbing - IFSC Climbing World Cup - Climbing Center Haslital, Meiringen, Switzerland - April 16, 2021 Austria’s Jessica Pilz during the women's qualifications REUTERS/Denis Balibouse

Climbing - IFSC Climbing World Cup - Climbing Center Haslital, Meiringen, Switzerland - April 16, 2021 Germany’s Alexander Megos during the men's qualifications REUTERS/Denis Balibouse

Climbing - IFSC Climbing World Cup - Climbing Center Haslital, Meiringen, Switzerland - April 16, 2021 USA’s Brooke Raboutou during the women's qualifications REUTERS/Denis Balibouse

Climbing - IFSC Climbing World Cup - Climbing Center Haslital, Meiringen, Switzerland - April 16, 2021 Nathaniel Coleman of the U.S. during the men's qualifications REUTERS/Denis Balibouse

Climbing - IFSC Climbing World Cup - Climbing Center Haslital, Meiringen, Switzerland - April 16, 2021 France’s Julia Chanourdie during the women's qualifications REUTERS/Denis Balibouse

A pregnant asylum-seeking woman stands on the American side after crossing on an inflatable raft the Rio Grande river from Mexico, in Roma, Texas, U.S., April 22, 2021. REUTERS/Jim Urquhart TPX IMAGES OF THE DAY

A woman washes clothes on the shore of Villa Victoria Dam, part of the Cutzamala System collecting water for distribution into Mexico City and the metropolitan area as it is running out of water as drought takes hold of the city of almost 22 million people, in Villa Victoria, State of Mexico, Mexico April 21, 2021. Picture taken with a drone. REUTERS/Carlos Jasso TPX IMAGES OF THE DAY

An employee walks at a control centre of the damaged fourth reactor at the Chernobyl Nuclear Power Plant in Chernobyl, Ukraine March 25, 2021. Picture taken March 25, 2021. REUTERS/Gleb Garanich TPX IMAGES OF THE DAY

Women sit at Imam Abbas shrine during the holy month of Ramadan in Kerbala, Iraq, April 22, 2021. REUTERS/Abdullah Dhiaa Al-deen TPX IMAGES OF THE DAY

Katie Wright, the mother of Daunte Wright touches her son in a casket during a viewing service, after he was shot and killed by Brooklyn Center Police officer Kim Potter, at his public viewing at Shiloh Temple International Ministries in Minneapolis, Minnesota, U.S., April 21, 2021. REUTERS/Octavio Jones TPX IMAGES OF THE DAY