A US Secret Service agent shot a man carrying a firearm near the White House, after the man refused to drop his weapon, the agency said.

The man was taken into custody and transported to a local hospital, agency spokesman David Iacovetti said on Friday.

"When the subject failed to comply with the verbal commands, he was shot once by a Secret Service agent and taken into custody," he said.

"The Secret Service recovered a firearm at the scene. Secret Service Uniformed Division Officers and an agent provided medical aid to the subject."

The man did not enter the White House complex and no law enforcement personnel or innocent bystanders were injured.

The checkpoint is on the outside perimeter of the secure area around the executive mansion in Washington DC, and is accessible on that side to the public.

The White House security alert was lifted soon after everyone inside was accounted for.

Source: Agencies