Trump abruptly escorted from briefing

He returned minutes later, saying there had been a "shooting" outside the White House that was "under control".

"There was an actual shooting and somebody's been taken to the hospital," Trump said on Monday afternoon.

The president said the shots were fired by law enforcement and he believed the individual who was shot was armed.

"It was the suspect who was shot," Trump said.

Trump said he was escorted to the Oval Office by the agent. The White House was placed on lockdown following the incident.

The shooting occurred after a 51-year-old man approached a uniformed Secret Service officer near 17th Street and Pennsylvania Avenue just blocks from the White House and told the officer he had a weapon, Tom Sullivan, chief of the Secret Service Uniformed Division, said on Monday night.

The man then turned around and "ran aggressively toward the officer, and in a drawing motion, removed an object from his clothing", Sullivan said.

The suspect then "crouched into a shooter's stance, as if about to fire a weapon" before the officer shot the man once in the torso, he said.

Sullivan would not answer any questions at a late-night news conference near the scene and did not say whether the suspect was armed.

The suspect and the officer were taken to the hospital. The District of Columbia fire department said the suspect suffered serious or possibly critical injuries. Sullivan released no information about the officer.

Law enforcement officials were still trying to determine the suspect's motive and authorities were investigating whether he has a history of mental illness. The suspect's name was not immediately released.

"At no time during this incident was the White House complex breached or were any protectees in danger," Sullivan said.

Trump praised the work of Secret Service personnel for their work in keeping him safe. Asked if he was shaken by the incident, Trump asked reporters: "I don't know. Do I seem rattled?"

Australian Associated Press