The local police said later that an "adult male has been declared deceased".
At about 11:46 a.m. EST., the man approached the North White House fence line.
The secret service further informed that no one else has been injured apart from the gunman.
The identity of the man, who suffered a single gunshot wound, has not been made public.
Police have roped off the area near the White House, and Pennsylvania Avenue has been shut down to pedestrians.
'We're sheltering in place at the White House briefing room. Officials are working on notifying his relatives, police said in the tweet. As they investigated the incident, agents could be seen sprinting across the north lawn and the executive driveway with their guns drawn. The White House Press said that Trump had been briefed on the situation.
President Trump is not at the White House. A Secret Service source confirmed to CNN that the victim's auto was located in the area where the search of the vehicle took place. No other injuries have been announced, and medical personnel were reported to be on the scene.
He spent the morning golfing in Mar-a-Lago and had not long returned to his residence there when news of the shooting emerged.
In his first tweet, the president said, "Mainstream Media in U.S.is being mocked all over the world".
The president is in Florida.