A gunman who opened fire outside the White House on Saturday evening has died after being shot, according to the US Secret Service.

In its preliminary statement regarding the shooting incident, the agency explained the suspect pulled a weapon from his bag and began firing.

The Secret Service Police returned fire and shot the suspect.

The suspect was later transported to an area hospital where he was pronounced deceased. A bystander was also struck by gunfire, the agency added.

It also said US President Donald Trump was in the White House during the incident, however no protectees or operations were impacted.

The incident remains under investigation.