Visitors wearing masks, following the novel coronavirus outbreak, visit the Military Museum of the Chinese People's Revolution in Beijing, China May 26, 2020. REUTERS/Tingshu Wang

Visitors wearing masks, following the novel coronavirus outbreak, visit the Military Museum of the Chinese People's Revolution in Beijing, China May 26, 2020. REUTERS/Tingshu Wang

Visitors wearing masks, following the novel coronavirus outbreak, visit the Military Museum of the Chinese People's Revolution in Beijing, China May 26, 2020. REUTERS/Tingshu Wang

Visitors watch video footage of Chinese President Xi Jinping reviewing the troops during the military parade marking the 70th founding anniversary of People's Republic of China on October 1, 2019, at the Military Museum of the Chinese People's Revolution in Beijing, China May 26, 2020. REUTERS/Tingshu Wang

Visitors watch video footage of Chinese People's Liberation Army (PLA) soldiers marching during the military parade marking the 70th founding anniversary of People's Republic of China on October 1, 2019, at the Military Museum of the Chinese People's Revolution in Beijing, China May 26, 2020. REUTERS/Tingshu Wang

A screen shows a video footage of Chinese President Xi Jinping gesturing during the military parade marking the 70th founding anniversary of People's Republic of China on October 1, 2019, at the Military Museum of the Chinese People's Revolution in Beijing, China May 26, 2020. REUTERS/Tingshu Wang

A visitor stands in front uniform exhibits of Chinese People's Liberation Army (PLA) personnel, which have been worn during the military parade marking the 70th founding anniversary of People's Republic of China on October 1, 2019, at an exhibition at the Military Museum of the Chinese People's Revolution in Beijing, China May 26, 2020. REUTERS/Tingshu Wang

Visitors wearing masks, following the novel coronavirus outbreak, visit the Military Museum of the Chinese People's Revolution in Beijing, China May 26, 2020. REUTERS/Tingshu Wang

Visitors wearing masks, following the novel coronavirus outbreak, visit the Military Museum of the Chinese People's Revolution in Beijing, China May 26, 2020. REUTERS/Tingshu Wang

The Rolling Thunder souvenir stand near the Lincoln Memorial is closed due to concerns about the coronavirus disease (COVID-19) in Washington, U.S., May 25, 2020. REUTERS/Erin Scott

Masked visitors to the Vietnam Memorial pay respects in Washington, U.S., May 25, 2020. REUTERS/Erin Scott

Members of Boy Scouts of America wearing protective masks salute at a ceremony for Veterans who are unable to give military honors as the Pandemic during Memorial Day following the outbreak of the coronavirus disease (COVID-19) in the Staten Island borough of New York U.S., May 25, 2020. REUTERS/Jeenah Moon

A member of Boy Scouts of America wearing a protective mask lays an U.S. flag in a ceremony for Veterans who are unable to give military honors during Memorial Day following the outbreak of the coronavirus disease (COVID-19) at Ocean View Cemetery in the Staten Island borough of New York U.S., May 25, 2020. REUTERS/Jeenah Moon

A member of Boy Scouts of America wearing a protective mask salutes at a ceremony for Veterans who are unable to give military honors during Memorial Day following the outbreak of the coronavirus disease (COVID-19) in the Staten Island borough of New York U.S., May 25, 2020. REUTERS/Jeenah Moon TPX IMAGES OF THE DAY

A member of Boy Scouts of America wearing a protective mask participates in a ceremony for Veterans who are unable to give military honors during Memorial Day following the outbreak of the coronavirus disease (COVID-19) at Ocean View Cemetery in the Staten Island borough of New York U.S., May 25, 2020. REUTERS/Jeenah Moon

U.S. President Donald Trump waves past a U.S. Secret Service agent wearing a protective face mask towards a member of the military as he departs after attending ceremonies commemorating the Memorial Day holiday in the midst of the COVID-19 pandemic at Fort McHenry in Baltimore, Maryland, U.S., May 25, 2020. REUTERS/Joshua Roberts

Members of the U.S. military, veterans and members of the public visit the Vietnam Veterans Memorial in the midst of the coronavirus disease (COVID-19) pandemic while commemorating the U.S. Memorial Day holiday in Washington, U.S., May 25, 2020. REUTERS/Michael A. McCoy

U.S. first lady Melania Trump is escorted by a military aide during a Memorial Day ceremony at Fort McHenry in Baltimore, Maryland, U.S., May 25, 2020. REUTERS/Joshua Roberts

U.S. President Donald Trump listens as a military fife and drum corps plays during ceremonies commemorating the Memorial Day holiday at Fort McHenry in Baltimore, Maryland, U.S., May 25, 2020. REUTERS/Joshua Roberts

U.S. President Donald Trump speaks as members of the U.S. military dressed in historical uniforms listen during ceremonies commemorating the Memorial Day holiday at Fort McHenry in Baltimore, Maryland, U.S., May 25, 2020. REUTERS/Joshua Roberts

Chairman of the Joint Chiefs of Staff Army Gen. Mark Milley walks between members of the U.S. military dressed in historical uniforms as he arrives with U.S. President Donald Trump to attend ceremonies commemorating the Memorial Day holiday at Fort McHenry in Baltimore, Maryland, U.S., May 25, 2020. REUTERS/Joshua Roberts

Chairman of the Joint Chiefs of Staff Army Gen. Mark Milley stands near members of the U.S. military dressed in historical uniforms as U.S. President Donald Trump attends ceremonies commemorating the Memorial Day holiday at Fort McHenry in Baltimore, Maryland, U.S., May 25, 2020. REUTERS/Joshua Roberts

Members of the U.S. military dressed in 19th century uniforms listen as U.S. President Donald Trump speaks during ceremonies commemorating the Memorial Day holiday at Fort McHenry in Baltimore, Maryland, U.S., May 25, 2020. REUTERS/Joshua Roberts

Members of the U.S. military dressed in 19th century uniforms await the arrival of U.S. President Donald Trump to attend ceremonies commemorating the Memorial Day holiday at Fort McHenry in Baltimore, Maryland, U.S., May 25, 2020. REUTERS/Joshua Roberts

A U.S. military fife and drum corps performs as U.S. President Donald Trump attends ceremonies commemorating the Memorial Day holiday at Fort McHenry in Baltimore, Maryland, U.S., May 25, 2020. REUTERS/Joshua Roberts

A U.S. military officer and President Donald Trump salute during a wreath laying ceremony at the Tomb of the Unknown Soldier at Arlington National Cemetery in commemoration of the Memorial Day holiday in Arlington, Virginia, U.S., May 25, 2020. REUTERS/Erin Scott

A woman holds a Jordanian national flag as Jordanian troops ride their military vehicles during a parade at a ceremony to celebrate the country's 74th Independence Day within a limited number of activities amid the spread of the coronavirus disease (COVID-19), in Amman, Jordan May 25, 2020. REUTERS/Muhammad Hamed

Jordanian troops ride their military vehicles during a parade at a ceremony to celebrate the country's 74th Independence Day within a limited number of activities amid the spread of the coronavirus disease (COVID-19), in Amman, Jordan May 25, 2020. REUTERS/Muhammad Hamed

Jordanian troops ride their military vehicles holding a picture of Jordan's King Abdullah during a parade at a ceremony to celebrate the country's 74th Independence Day within a limited number of activities amid the spread of the coronavirus disease (COVID-19), in Amman, Jordan May 25, 2020. REUTERS/Muhammad Hamed

A U.S. military officer salutes and first lady Melania Trump watches as President Donald Trump salutes while participating in a wreath laying ceremony at the Tomb of the Unknown Soldier at Arlington National Cemetery near Washington in commemoration of the Memorial Day holiday in Arlington, Virginia, U.S., May 25, 2020. REUTERS/Erin Scott

A member of the Spanish Emergency Military Unit (UME) wearing a full personal protective equipment disinfects outside the Archaeological Museum amid the coronavirus disease (COVID-19) outbreak, in Madrid, Spain May 25, 2020. REUTERS/Sergio Perez

Members of the Spanish Emergency Military Unit (UME) wearing full personal protective equipments disinfect outside the Archaeological Museum amid the coronavirus disease (COVID-19) outbreak, in Madrid, Spain May 25, 2020. REUTERS/Sergio Perez

A member of the Spanish Emergency Military Unit (UME) wearing a full personal protective equipment disinfects outside the Archaeological Museum amid the coronavirus disease (COVID-19) outbreak, in Madrid, Spain May 25, 2020. REUTERS/Sergio Perez

Zhang Youxia, vice chairman of the Central Military Commission, attends the second plenary session of the National People's Congress (NPC) at the Great Hall of the People in Beijing, China May 25, 2020. REUTERS/Thomas Peter

Xu Qiliang, vice chairman of the Central Military Commission, attends the second plenary session of the National People's Congress (NPC) at the Great Hall of the People in Beijing, China May 25, 2020. REUTERS/Thomas Peter

Military delegates wearing face masks arrive for the second plenary session of the National People's Congress (NPC) at the Great Hall of the People in Beijing, China May 25, 2020. REUTERS/Thomas Peter

Flowers lay near crosses during a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Final preparations prior a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

A worker disinfects the lectern after a speaker during a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch King Willem-Alexander and U.S. ambassador Peter Hoekstra attend a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

A worker disinfects the lectern after a speaker during a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

A worker disinfects the lectern after a speaker during a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Crosses are seen during a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch and U.S. flags are seen during a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

F-16 fighter jets of the Royal Netherlands Air Force perform a flyover during a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch and U.S. flags are seen during a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch and U.S. flags are seen at half-mast a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

U.S. ambassador Peter Hoekstra attends a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch King Willem-Alexander and U.S. ambassador Peter Hoekstra attend a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch King Willem-Alexander and U.S. ambassador Peter Hoekstra attend a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch King Willem-Alexander and U.S. ambassador Peter Hoekstra attend a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch King Willem-Alexander attends a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch King Willem-Alexander attends a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch King Willem-Alexander attends a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch King Willem-Alexander and U.S. ambassador Peter Hoekstra attend a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch King Willem-Alexander and U.S. ambassador Peter Hoekstra attend a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch King Willem-Alexander and U.S. ambassador Peter Hoekstra attend a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch King Willem-Alexander and U.S. ambassador Peter Hoekstra attend a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch King Willem-Alexander and U.S. ambassador Peter Hoekstra attend a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS

Dutch King Willem-Alexander and U.S. ambassador Peter Hoekstra attend a ceremony commemorating over 10,000 U.S. Second World War military dead buried or remembered at the Netherlands American Cemetery and Memorial in Margraten, Netherlands May 24, 2020. Marcel Van Hoorn/Pool via REUTERS