U.S. Secretary of State Rex Tillerson listens as President Donald Trump holds a cabinet meeting at the White House in Washington, U.S., October 16, 2017.

A young boy holds the American flag in front of his face as U.S. President Donald Trump arrives at a campaign rally in Springfield, Missouri, U.S., September 21, 2018.

President Donald Trump salutes a U.S. Border Patrol helicopter with U.S. Border Patrol agents as it flies over the Rio Grande River during his visit to the U.S. - Mexico border in Mission, Texas, U.S., January 10, 2019.

White House senior adviser Ivanka Trump and her husband senior adviser Jared Kushner walk along the South Lawn of the White House in Washington, U.S., as they accompanied U.S. President Donald Trump before his departure to New York May 4, 2017.

Former campaign manager Corey Lewandowski (C) says hello to reporters as he and White House advisors Sebastian Gorka (from L), Omarosa Manigault, White House Staff Secretary Rob Porter and Communications Director Anthony Scaramucci accompany President Trump for an event celebrating veterans at AMVETS Post 44 in Struthers, Ohio, U.S. July 25, 2017.

U.S. President Donald Trump gestures to reporters as Russian flags thrown from a protester fall in front of the president and Senate Majority Leader Mitch McConnell (R-KY) as they arrive for the Republican policy luncheon on Capitol Hill in Washington, U.S., October 24, 2017.

Germany's Chancellor Angela Merkel and U.S. President Donald Trump hold a joint news conference in the East Room of the White House in Washington, U.S., March 17, 2017.

White House Chief of Staff John Kelly waits behind the Resolute Desk as U.S. President Donald Trump delivers remarks to reporters as he welcomes United Nations Secretary General Antonio Guterres for a meeting in the Oval Office at the White House in Washington, U.S. October 20, 2017.

U.S. President Donald Trump greets Director of the FBI James Comey as Director of the Secret Service Joseph Clancy (L) watches during the Inaugural Law Enforcement Officers and First Responders Reception in the Blue Room of the White House in Washington, U.S., January 22, 2017.

U.S. President Donald Trump observes a demonstration with U.S. Army 10th Mountain Division troops, an attack helicopter and artillery as he visits Fort Drum, New York, U.S., August 13, 2018. REUTERS/Carlos Barria

Trump advisers Steve Bannon (back L) and Jared Kushner (back R) listen as U.S. President Donald Trump meets with members of his Cabinet at the White House in Washington, U.S., June 12, 2017.

U.S. first lady Melania Trump looks on during a meeting between U.S. President Donald Trump and Poland's President Andrzej Duda in the Oval Office of the White House in Washington, U.S., September 18, 2018.

U.S. President Donald Trump attends a campaign rally for Republican U.S. Senate candidate Matt Rosendale at the Bozeman Yellowstone International Airport in Belgrade, Montana, U.S., November 3, 2018.

U.S. President Donald Trump and Saudi Arabia's Crown Prince Mohammed bin Salman are seen during the G20 summit in Buenos Aires, Argentina November 30, 2018.

U.S. President Donald Trump, first lady Melania Trump, former President Barack Obama, former first lady Michelle Obama, former President Bill Clinton, former Secretary of State Hillary Clinton, former President Jimmy Carter and former first lady Rosalynn Carter participate in the State Funeral for former President George H.W. Bush, at the National Cathedral, Wednesday, Dec. 5, 2018 in Washington.

Special Counsel Robert Mueller departs after briefing members of the U.S. Senate on his investigation of potential collusion between Russia and the Trump campaign on Capitol Hill in Washington, U.S., June 21, 2017.

U.S. President Donald Trump (L-R), joined by Chief of Staff Reince Priebus, Vice President Mike Pence, senior advisor Steve Bannon, Communications Director Sean Spicer and National Security Advisor Michael Flynn, speaks by phone with Russia's President Vladimir Putin in the Oval Office at the White House in Washington, U.S. January 28, 2017.

U.S. President Donald Trump welcomes 11-year-old Frank Giaccio as he cuts the Rose Garden grass at the White House in Washington, U.S., September 15, 2017. Frank, who wrote a letter to Trump offering to mow the White House lawn, was invited to work for a day at the White House along the National Park Service staff.

U.S. President Donald Trump speaks with reporters at the White House in Washington, U.S. November 28, 2017.

U.S. President Donald Trump reacts as he sits in a truck while he welcomes truckers and CEOs to attend a meeting regarding healthcare at the White House in Washington, U.S., March 23, 2017.

U.S. President Donald Trump speaks while participating in a tour of U.S.-Mexico border wall prototypes near the Otay Mesa Port of Entry in San Diego, California. U.S., March 13, 2018.

U.S. President Donald Trump speaks in front of fast food provided for the 2018 College Football Playoff National Champion Clemson Tigers due to the partial government shutdown in the State Dining Room of the White House in Washington, U.S., January 14, 2019.

U.S. President Donald Trump visits the Skyway Villa Mobile Home and RV Park, a neighborhood recently destroyed by the Camp Fire, with Governors of California Jerry Brown, right, Mayor Jody Jones, second from right, Brock Long, back left, and Governor-elect Gavin Newsom in Paradise, California, U.S., November 17, 2018.

U.S. President Donald Trump speaks during an interview with Reuters in the Oval Office of the White House in Washington, U.S., April 27, 2017.

U.S. President Donald Trump embraces a boy while helping hand out meals with North Carolina Governor Roy Cooper (L) at a distribution center at Temple Baptist Church while participating in a tour of Hurricane Florence recovery efforts in New Bern, North Carolina, U.S., September 19, 2018.

U.S. President-elect Donald Trump arrives for the inauguration ceremonies swearing him in as the 45th president of the United States on the West front of the U.S. Capitol in Washington, U.S., January 20, 2017.

U.S. President Donald Trump speaks during a bill signing event for "America's Water Infrastructure Act of 2018" in the Oval Office at the White House in Washington, U.S., October 23, 2018.

U.S. President Donald Trump speaks next to Vice President Mike Pence (2ndL) while meeting with Senate Democratic Leader Chuck Schumer (D-NY) and House Democratic Leader Nancy Pelosi (D-CA) at the White House in Washington, U.S., December 11, 2018.

Michael Cohen, U.S. President Donald Trump's former attorney, arrives for his sentencing at United States Court house in the Manhattan borough of New York City, New York, U.S., December 12, 2018. REUTERS/Shannon Stapleton - RC1DFED7CF30

U.S. President Donald Trump and First Lady Melania Trump greet military personnel at the dining facility during an unannounced visit to Al Asad Air Base, Iraq December 26, 2018. Reuters/Jonathan Ernst

U.S. President Donald Trump (C) and other leaders react to a wall of computer screens coming online as they tour the Global Center for Combatting Extremist Ideology in Riyadh, Saudi Arabia May 21, 2017.

U.S. President Donald Trump throws rolls of paper towels into a crowd of local residents affected by Hurricane Maria as he visits Calgary Chapel in San Juan, Puerto Rico, U.S., October 3, 2017.

U.S. President Donald Trump delivers his first State of the Union address to a joint session of Congress inside the House Chamber on Capitol Hill in Washington, U.S., January 30, 2018.