Secret service agents stand in the doorway of Delaware Imaging Network as President-elect Joe Biden arrives to receive a CT scan after twisting his ankle while playing with his dog Major in Newark, Delaware, U.S., November 29, 2020. REUTERS/Joshua Roberts

Secret service agents stand in the doorway of Delaware Imaging Network as President-elect Joe Biden arrives to receive a CT scan after twisting his ankle while playing with his dog Major in Newark, Delaware, U.S., November 29, 2020. REUTERS/Joshua Roberts

A Secret Service agent waits for President-elect Joe Biden to enter the Delaware Orthopaedic Specialists clinic after twisting his ankle while playing with his dog Major, in Newark, Delaware, U.S., November 29, 2020. REUTERS/Joshua Roberts

Shoppers stand in line as they wait for a Victoria's Secret store to open on Black Friday, at the Tysons Corner Center, in Tysons, Virginia, U.S., November 27, 2020. REUTERS/Hannah McKay

Shoppers stand in line as they wait for a Victoria's Secret store to open on Black Friday, at the Tysons Corner Center, in Tysons, Virginia, U.S., November 27, 2020. REUTERS/Hannah McKay

Miomir Korac, lead archaeologist, poses for a picture at the remains of Roman legion's headquarters at the ancient city of Viminacium, near Kostolac, Serbia, November 25, 2020. Picture taken November 25, 2020. REUTERS/Marko Djurica

An archaeologist excavates the remains of Roman legion's headquarters at the ancient city of Viminacium, near Kostolac, Serbia, November 25, 2020. Picture taken November 25, 2020. REUTERS/Marko Djurica

Silver coins found at the remains of a Roman legion's headquarters are seen at the ancient city of Viminacium, near Kostolac, Serbia, November 25, 2020. Picture taken November 25, 2020. REUTERS/Marko Djurica

Archaeologists excavate the remains of Roman legion's headquarters at the ancient city of Viminacium, near Kostolac, Serbia, November 25, 2020. Picture taken November 25, 2020. REUTERS/Marko Djurica

Archaeologists excavate the remains of Roman legion's headquarters at the ancient city of Viminacium, near Kostolac, Serbia, November 25, 2020. Picture taken November 25, 2020. REUTERS/Marko Djurica

Archaeologists excavate the remains of Roman legion's headquarters at the ancient city of Viminacium, near Kostolac, Serbia, November 25, 2020. Picture taken November 25, 2020. Picture taken with a drone. REUTERS/Marko Djurica

Archaeologists excavate the remains of Roman legion's headquarters at the ancient city of Viminacium, near Kostolac, Serbia, November 25, 2020. Picture taken November 25, 2020. Picture taken with a drone. REUTERS/Marko Djurica

Archaeologists excavate the remains of Roman legion's headquarters at the ancient city of Viminacium, near Kostolac, Serbia, November 25, 2020. Picture taken November 25, 2020. Picture taken with a drone. REUTERS/Marko Djurica

Archaeologists excavate the remains of Roman legion's headquarters at the ancient city of Viminacium, near Kostolac, Serbia, November 25, 2020. Picture taken November 25, 2020. Picture taken with a drone. REUTERS/Marko Djurica

Shoppers wearing mandatory masks pass a Victoria's Secret store, two days before coronavirus disease (COVID-19) restrictions are reintroduced to Greater Toronto Area regions, at Eaton Centre mall in downtown Toronto, Ontario, Canada November 21, 2020. REUTERS/Chris Helgren

A U.S. Secret Service agent wearing a protective face mask stands at his post in the Rose Garden, in front of a line of White House staff members, as President Donald Trump delivers an update on the so-called "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, at the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

A U.S. Secret Service agent wearing a protective face mask stands at her post on the West Wing colonnade outside the Oval Office waiting for the president to walk out to the Rose Garden to deliver an update on the so-called "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, at the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

Aides and Secret Service agents watch as U.S. President-elect Joe Biden takes questions after remarks on healthcare at the theater serving as his transition headquarters in Wilmington, Delaware, U.S. November 10, 2020. REUTERS/Jonathan Ernst

U.S. Secret Service counter snipers walk off of the rooftop during a shift change at the White House in Washington, U.S., November 10, 2020. REUTERS/Tom Brenner

A U.S. Secret Service agent stands guard outside the church where U.S. President-elect Joe Biden is attending a service, in Wilmington, Delaware, U.S., November 8, 2020. REUTERS/Jonathan Ernst

Biden supporters unable to reach the watch party due to Secret Service road blocks congregate below the Philadelphia 76ers facility in Wilmington, after news media named Democratic presidential nominee Joe Biden the winner in the 2020 U.S. presidential election, Delaware, U.S. November 7, 2020. REUTERS/Mark Makela TPX IMAGES OF THE DAY

A United States Secret Service Agent stands guard outside of the North Portico doors at the White House in Washington, U.S., November 6, 2020. REUTERS/Tom Brenner

A member of U.S. Secret Service guards the entrance to the site where the former Vice President Joe Biden and Senator Kamala Harris hope to celebrate their victory in the U.S. presidential race in Wilmington, Delaware, U.S., November 5, 2020. REUTERS/Leah Millis

United States Secret Service Agents walk past the West Wing as journalists continue to wait for news after early results in the 2020 U.S. Presidential election at the White House in Washington, U.S., November 4, 2020. REUTERS/Tom Brenner

A U.S. Secret Service agent stands guard behind protective fencing at the New Eisenhower Executive Office Building near the White House, after early results of the 2020 U.S. presidential election were announced, in Washington, U.S., November 4, 2020. REUTERS/Tom Brenner

A U.S. Secret Service Agent keeps watch as U.S. President Donald Trump departs the White House on Election Day in Washington, U.S., November 3, 2020. REUTERS/Tom Brenner

A United States Secret Service Officer stands guard behind a supplemental protective fence barricade outside of the New Eisenhower Executive Office Building in preparation for Election Day protests, in Washington, U.S., November 3, 2020. REUTERS/Tom Brenner

A United States Secret Service Officer stands guard behind a supplemental protective fence barricade outside of the New Eisenhower Executive Office Building in preparation for Election Day protests, in Washington, U.S., November 3, 2020. REUTERS/Tom Brenner

United States Secret Service Counter Snipers stand guard beside a rife at a neighboring rooftop during a campaign rally for U.S. President Donald Trump in Avoca, Pennsylvania, U.S., on November 2, 2020. REUTERS/Tom Brenner TPX IMAGES OF THE DAY

A U.S. Secret Service agent watches a construction site on the South side of the White House, the day before the U.S. presidential election, in Washington, U.S., November 2, 2020. REUTERS/Erin Scott

A Secret Service agent keeps watch before a campaign rally by U.S. President Donald Trump at Hickory Regional Airport in Hickory, North Carolina U.S., November 1, 2020. REUTERS/Hannah McKay

United States Secret Service Counter Sniper personnel scan a neighboring field with binoculars during a presidential campaign rally for U.S. President Donald Trump in Newtown, Pennsylvania, U.S., on October 31, 2020. REUTERS/Tom Brenner

United States Secret Service Agents stand guard beside the stage as U.S. President Donald Trump delivers remarks at a campaign rally in Newtown, Pennsylvania, U.S., on October 31, 2020. REUTERS/Tom Brenner

A United States Secret Service Officer stands guard in a nearby field ahead of a presidential campaign rally for U.S. President Donald Trump in Newtown, Pennsylvania, U.S., on October 31, 2020. REUTERS/Tom Brenner

A member of the U.S. Secret Service walks on the roof of the White House, in Washington D.C., U.S., October 30, 2020. REUTERS/Hannah McKay

Secret Service Agents stand near U.S. President Donald Trump during a campaign event at La Crosse Speedway in West Salem, Wisconsin, U.S. October 27, 2020. REUTERS/Jonathan Ernst REFILE - CORRECTING TYPO

U.S. Vice President Mike Pence runs from his plane to the podium while a secret service agent keeps pace with him as they arrive at a rally in Kinston, North Carolina, U.S., October 25, 2020. REUTERS/Jonathan Drake TPX IMAGES OF THE DAY

Secret Service agents keep watch as U.S. Democratic presidential candidate Joe Biden emerges from church in Wilmington, Delaware, U.S., October 25, 2020. REUTERS/Kevin Lamarque

A United States Secret Service presidential limousine driver looks on while wearing a protective face mask as U.S. President Donald Trump walks to the podium during a campaign event at the Waukesha County Airport in Waukesha, Wisconsin, U.S., on October 24, 2020. REUTERS/Tom Brenner

A United States Secret Service counter sniper looks on from a rooftop as U.S. President Donald Trump walks on stage at a campaign event at the Robeson County Fairgrounds in Lumberton, North Carolina, U.S., October 24, 2020. REUTERS/Tom Brenner

Surrounded by Secret Service, U.S. Democratic presidential candidate Joe Biden walks to his motorcade vehicle in downtown Wilmington, Delaware, U.S., October 23, 2020. REUTERS/Kevin Lamarque

Surrounded by Secret Service, U.S. Democratic presidential candidate Joe Biden waves as he walks to his motorcade vehicle in downtown Wilmington, Delaware, U.S., October 23, 2020. REUTERS/Kevin Lamarque

Secret service detail of U.S. Democratic vice presidential nominee Senator Kamala Harris (D-CA) wait for her to deplane before attending a campaign event in Atlanta, Georgia, U.S., October 23, 2020. REUTERS/Dustin Chambers

Secret service detail of U.S. Democratic vice presidential nominee Senator Kamala Harris (D-CA) wait for her to deplane before attending a campaign event in Atlanta, Georgia, U.S., October 23, 2020. REUTERS/Dustin Chambers

A U.S. Secret Service agent stands by the stage before the second 2020 presidential campaign debate between U.S. President Donald Trump and Democratic presidential nominee Joe Biden at Belmont University in Nashville, Tennessee, U.S., October 22, 2020. REUTERS/Mike Segar

Secret service personnel stand guard as U.S. President Donald Trump holds a campaign rally in Gastonia, North Carolina, U.S., October 21, 2020. REUTERS/Tom Brenner

An impersonator of U.S. President Donald Trump walks with a man dressed as a member of the secret service as Trump supporters march in the Manhattan borough of New York, U.S. October 21, 2020. REUTERS/Yuki Iwamura

A woman walks in front of plywoods covering the windows of a Victoria's Secret store in Chicago, Illinois, U.S. October 13, 2020. Chicago police have warned local retailers to prepare for possible protests around Election Day. Picture taken October 13, 2020. REUTERS/Moe Zoyari

Democratic U.S. presidential nominee Joe Biden is seen reflected in the sunglasses of a U.S. Secret Service agent as the agent holds the door for Biden when he leaves The Queen after doing an interview with 60 Minutes in Wilmington, Delaware, U.S., October 19, 2020. REUTERS/Leah Millis TPX IMAGES OF THE DAY

A U.S. Secret Service agent is seen as U.S. President Donald Trump holds a campaign rally in Carson City, Nevada, U.S., October 18, 2020. REUTERS/Carlos Barria

United States Secret Service agents open the door to U.S. Democratic presidential candidate Joe Biden's vehicle before he boards his campaign plane at the Raleigh-Durham International Airport in Durham, North Carolina, U.S., October 18, 2020. REUTERS/Tom Brenner

United States Secret Service agents open the door to U.S. Democratic presidential candidate Joe Biden's vehicle before he boards his campaign plane at the Raleigh-Durham International Airport in Durham, North Carolina, U.S., October 18, 2020. REUTERS/Tom Brenner

A United States Secret Service Agent stands guard ahead of Democratic presidential candidate Joe Biden's remarks during a Vision for Older Americans event at the Southwest Focal Point Community Center, in Pembroke Pines, Florida, U.S., October 13, 2020. REUTERS/Tom Brenner

A United States Secret Service Agent stands guard ahead of Democratic presidential candidate Joe Biden's remarks during a Vision for Older Americans event at the Southwest Focal Point Community Center, in Pembroke Pines, Florida, U.S., October 13, 2020. REUTERS/Tom Brenner

A United States Secret Service Agent walks past the viewing area for the White House South Portico at sunrise, near Ellipse Park in Washington, U.S., October 9, 2020. REUTERS/Tom Brenner

A United States Secret Service Agent walks past the viewing area for the White House South Portico at sunrise, near Ellipse Park in Washington, U.S., October 9, 2020. REUTERS/Tom Brenner

A U.S. Secret Service agent sanitizes Vice President Mike Pence's desk as a coronavirus disease (COVID-19) precaution before Democratic vice presidential nominee Senator Kamala Harris and U.S. Vice President Mike Pence participate in their 2020 vice presidential campaign debate held on the campus of the University of Utah in Salt Lake City, Utah, U.S., October 7, 2020. REUTERS/Lucy Nicholson TPX IMAGES OF THE DAY

A U.S. Secret Service agent stands at his post in the debate hall before the 2020 vice presidential campaign debate held on the campus of the University of Utah in Salt Lake City, Utah, U.S., October 7, 2020. REUTERS/Brian Snyder

Secret Service agents keep watch as Democratic U.S. presidential nominee Joe Biden speaks during a campaign stop in Gettysburg, Pennsylvania, U.S., October 6, 2020. REUTERS/Kevin Lamarque