The Marine One helicopter carrying U.S. President Donald Trump, flies past the Washington Monument and the Jefferson Memorial as it arrives back at the White House after traveling to Fort McHenry in Baltimore for Memorial Day holiday commemorations, in Washington, U.S., May 25, 2020. REUTERS/Erin Scott

Clouds cover the Washington Monument seen from the National Mall, largely empty of tourists during the coronavirus disease (COVID-19) outbreak in Washington, U.S., May 22, 2020. Picture taken May 22, 2020. REUTERS/Jonathan Ernst

U.S. President Donald Trump heads to the Marine One helicopter with the Washington Monument in the background as he departs on travel to Allentown, Pennsylvania from the South Lawn of the White House in Washington, U.S., May 14, 2020. REUTERS/Tom Brenner

U.S. President Donald Trump talks to reporters with the Washington Monument in the background as he departs on travel to Allentown, Pennsylvania from the South Lawn of the White House in Washington, U.S., May 14, 2020. REUTERS/Tom Brenner

The Washington Monument and the Lincoln Memorial Reflecting Pool are seen at sunset from inside the memorial as U.S. President Donald Trump participates in a Fox News Channel virtual town hall called "America Together: Returning to Work" about the response to the coronavirus disease (COVID-19) pandemic broadcast from inside the memorial in Washington, U.S. May 3, 2020. REUTERS/Joshua Roberts

A formation of the U.S. Navy Blue Angels and the U.S. Air Force Thunderbirds fly past the Washington Monument as a collaborative salute to first responders and other essential personnel during the coronavirus disease (COVID-19) outbreak in Washington, U.S., May 2, 2020. REUTERS/Joshua Roberts TPX IMAGES OF THE DAY

A formation of the U.S. Navy Blue Angels and the U.S. Air Force Thunderbirds fly past the Washington Monument as a collaborative salute to first responders and other essential personnel during the coronavirus disease (COVID-19) outbreak in Washington, U.S., May 2, 2020. REUTERS/Joshua Roberts

A formation of the U.S. Navy Blue Angels and the U.S. Air Force Thunderbirds fly past the Washington Monument as a collaborative salute to first responders and other essential personnel during the coronavirus disease (COVID-19) outbreak in Washington, U.S., May 2, 2020. REUTERS/Joshua Roberts

A bird flies past Washington Monument with a formation of the U.S. Navy Blue Angels and the U.S. Air Force Thunderbirds in the background, as they fly over the National Mall as a collaborative salute to first responders and other essential personnel during the coronavirus disease (COVID-19) pandemic in Washington, U.S., May 2, 2020. REUTERS/Joshua Roberts

A bird flies past Washington Monument with a formation of the U.S. Navy Blue Angels and the U.S. Air Force Thunderbirds in the background, as they fly over the National Mall as a collaborative salute to first responders and other essential personnel during the coronavirus disease (COVID-19) pandemic in Washington, U.S., May 2, 2020. REUTERS/Joshua Roberts

The U.S. Capitol is seen from the Washington Monument, amid the spread of the coronavirus disease (COVID-19), in Washington, U.S., April 25, 2020. REUTERS/Erin Scott

Visitors to the Washington Monument pose for a photo, amid the spread of the coronavirus disease (COVID-19), in Washington, U.S., April 25, 2020. REUTERS/Erin Scott

Guy Capoeman, an artist, stands next to a totem pole, a monumental carving which is a type of Northwest Coast art, that he carved of a woman holding a fish, at Quinault Indian Nation's main village, on the Quinault Indian Reservation in Taholah, Washington, U.S., March 6, 2020. REUTERS/Stephanie Keith SEARCH ''QUINAULT CLIMATE CHANGE'' FOR THIS STORY. SEARCH ''WIDER IMAGE'' FOR ALL STORIES.

A supermoon rises over the U.S. Capitol, Washington Monument and Lincoln Memorial in Washington, U.S. April 7, 2020. REUTERS/Jonathan Ernst

The National Mall and grounds of the Washington Monument remain largely empty to try to limit the spread of Covid-19 during the coronavirus disease pandemic in Washington, U.S. April 7, 2020. REUTERS/Jonathan Ernst

A U.S. Park Police officer stands guard at the Lincoln Memorial, with a view of the Washington Monument in front of him, as the spread of the coronavirus disease (COVID-19) continues, in Washington, U.S. April 3, 2020. Picture taken April 3, 2020. REUTERS/Leah Millis

A cyclist stops in front of the Lincoln Memorial Reflecting Pool, with the Washington Monument lit by the setting sun at rear, as the spread of the coronavirus disease (COVID-19) continues in Washington, U.S. April 3, 2020. Picture taken April 3, 2020. REUTERS/Leah Millis

A cyclist stops in front of the Lincoln Memorial Reflecting Pool, with the Washington Monument lit by the setting sun at rear, as the spread of the coronavirus disease (COVID-19) continues in Washington, U.S. April 3, 2020. Picture taken April 3, 2020. REUTERS/Leah Millis TPX IMAGES OF THE DAY

The figure on a monument to the Marquis de Lafayette frames the empty plaza during the coronavirus outbreak, at the White House on Pennsylvania Avenue in Washington, U.S. March 30, 2020. Picture taken March 30, 2020. REUTERS/Jonathan Ernst

People pose for photographs near the Washington Monument, as the spread of coronavirus disease (COVID-19) continues, in Washington, U.S., March 23, 2020. REUTERS/Leah Millis

A lone person rides a bike around Washington Monument, as the spread of coronavirus disease (COVID-19) continues, in Washington, U.S., March 23, 2020. REUTERS/Leah Millis

"Grief holds her covered face against the shoulder of History and weeps in mourning" as depicted at the Peace Monument in front of the U.S. Capitol in Washington, U.S., March 23, 2020. The U.S. Senate struggled to reach agreement on a far-reaching coronavirus stimulus package on Monday. REUTERS/Kevin Lamarque

The Washington Monument is seen through a wooden fence, as Mayor Muriel Bowser issues a State of Emergency in response to the coronavirus disease (COVID-19) in Washington, U.S., March 20, 2020. REUTERS/Tom Brenner

The Washington Monument is seen through daffodil flowers on Columbia Island, as Mayor Muriel Bowser issues a State of Emergency in response to the coronavirus disease (COVID-19) in Washington, U.S., March 20, 2020. REUTERS/Tom Brenner

The Washington Monument is seen through daffodil flowers on Columbia Island, as Mayor Muriel Bowser issues a State of Emergency in response to the coronavirus disease (COVID-19) in Washington, U.S., March 20, 2020. REUTERS/Tom Brenner

The Washington Monument is seen through daffodil flowers on Columbia Island, as Mayor Muriel Bowser issues a State of Emergency in response to the coronavirus disease (COVID-19) in Washington, U.S., March 20, 2020. REUTERS/Tom Brenner

People walk past a reflection of the Washington Monument during a global outbreak of coronavirus disease (COVID-19) in Washington, U.S., March 19, 2020. REUTERS/Joshua Roberts

A man sits alone looking towards the Washington Monument amid a dramatic downturn in tourists due to the coronavirus pandemic in Washington, U.S., March 16, 2020. REUTERS/Kevin Lamarque

A closure note due to coronavirus disease (COVID-19) is seen at the entrance to the Washington Monument in Washington, U.S., March 14, 2020. REUTERS/Yuri Gripas

A closure note due to coronavirus disease (COVID-19) is seen at the entrance to the Washington Monument in Washington, U.S., March 14, 2020. REUTERS/Yuri Gripas

A closure note due to coronavirus disease (COVID-19) is seen at a ticket office to visit the Washington Monument in Washington, U.S., March 14, 2020. REUTERS/Yuri Gripas

A sign in the window of the entrance to the Washington Monument tells visitors that the tourist attraction in the U.S. capital is closed to the public due to the coronavirus threat, in Washington, U.S., March 14, 2020. REUTERS/Will Dunham

U.S. National Park Service ranger stands next to a closure note due to coronavirus disease (COVID-19) at the Washington Monument in Washington, U.S., March 14, 2020. REUTERS/Yuri Gripas

A member of the National Park Service closes the entry door for the National Monument as museums and many public areas are closed to the public for precaution due to coronavirus (COVID-19) spread, in Washington, U.S., March 14, 2020. REUTERS/Carlos Barria

People gather at the base of the Washington Monument at the National Mall in Washington, U.S., March 8, 2020. Picture taken March 8, 2020. REUTERS/Gleb Garanich

A statue representing "Grief" lays her covered face on the shoulder of the statue representing "History" on the Peace Monument near the U.S. Capitol where the Senate impeachment trial of President Donald Trump is going on in Washington, U.S., January 31, 2020. REUTERS/Mary F. Calvert

A statue representing "Grief" lays her covered face on the shoulder of the statue representing "History" on the Peace Monument near the U.S. Capitol where the Senate impeachment trial of President Donald Trump is going on in Washington, U.S., January 31, 2020. REUTERS/Mary F. Calvert

A statue representing "Grief" lays her covered face on the shoulder of the statue representing "History" on the Peace Monument near the U.S. Capitol where the Senate impeachment trial of President Donald Trump is going on in Washington, U.S., January 31, 2020. REUTERS/Mary F. Calvert

A statue representing "Grief" lays her covered face on the shoulder of the statue representing "History" on the Peace Monument near the U.S. Capitol where the Senate impeachment trial of President Donald Trump is going on in Washington, U.S., January 31, 2020. REUTERS/Mary F. Calvert TPX IMAGES OF THE DAY

A statue representing "Grief" lays her covered face on the shoulder of the statue representing "History" on the Peace Monument near the U.S. Capitol where the Senate impeachment trial of President Donald Trump is going on in Washington, U.S., January 31, 2020. REUTERS/Mary F. Calvert

A statue representing "Grief" lays her covered face on the shoulder of the statue representing "History" on the Peace Monument near the U.S. Capitol where the Senate impeachment trial of President Donald Trump is going on in Washington, U.S., January 31, 2020. REUTERS/Mary F. Calvert

A light fixture is reflected above the Washington Monument in a U.S. Capitol window ahead of a vote in the Senate, on Capitol Hill in Washington, U.S., January 13, 2020. REUTERS/Tom Brenner

A woman runs by the Washington Monument on the National Mall in Washington, D.C., U.S., January 12, 2020. REUTERS/Lucy Nicholson

A person poses for a photo ahead of the Washington Monument along the reflecting pool at the Lincoln Memorial during a snowstorm in Washington, U.S., January 7, 2020. REUTERS/Tom Brenner

Seagulls fly across the Washington Monument during a snowstorm in Washington, U.S., January 7, 2020. REUTERS/Tom Brenner

A jogger runs along the Washington Monument at sunrise following the U.S. House of Representatives previous-day vote to impeach U.S. President Donald Trump, in Washington, U.S., December 19, 2019. REUTERS/Tom Brenner

The Peace Monument stands in front of the U.S. Capitol prior to a vote in the U.S. House of Representatives on two articles of impeachment against U.S. President Donald Trump in Washington, U.S., December 18, 2019. REUTERS/Joshua Roberts

Rain falls over the Washington Monument in Washington, U.S., December 4, 2019. REUTERS/Joshua Roberts

The Washington Monument is seen during morning sunrise, ahead of a House Judiciary Committee impeachment hearing on Capitol Hill in Washington, D.C., U.S., December 4, 2019. REUTERS/Tom Brenner

The Washington Monument at the National Mall is pictured behind tourists in Washington, U.S., November 28, 2019. REUTERS/Loren Elliott

Tourists take a selfie at the base of the Washington Monument at the National Mall in Washington, U.S., November 28, 2019. REUTERS/Loren Elliott

A group of people walk past the Washington Monument at the National Mall in Washington, U.S., November 28, 2019. REUTERS/Loren Elliott

Tourists are pictured at the base of the Washington Monument at the National Mall in Washington, U.S., November 28, 2019. REUTERS/Loren Elliott

Bicyclists ride past the Washington Monument at the National Mall in Washington, U.S., November 28, 2019. REUTERS/Loren Elliott

Tourists are pictured at the base of the Washington Monument at the National Mall in Washington, U.S., November 28, 2019. REUTERS/Loren Elliott

American flags wave in the wind behind tourists standing in line at the base of the Washington Monument in Washington, U.S., November 28, 2019. REUTERS/Loren Elliott

The Washington Monument at the National Mall is pictured in Washington, U.S., November 28, 2019. REUTERS/Loren Elliott

A child poses for a photo at the base of the Washington Monument at the National Mall in Washington, U.S., November 28, 2019. REUTERS/Loren Elliott

Tourists are pictured at the base of the Washington Monument at the National Mall in Washington, U.S., November 28, 2019. REUTERS/Loren Elliott

The Washington Monument at the National Mall is pictured behind a tourist taking a selfie in Washington, U.S., November 28, 2019. REUTERS/Loren Elliott