The US President tripped and fell onstage at the commencement ceremony at the U.S. Air Force Academy in Colorado on Thursday as he returned to his seat after nearly two hours of shaking hands with graduates.

Iran PressAmerica: Joe Biden was walking across the raised platform when he stumbled over a black sandbag and fell to the ground. He was quickly helped to his feet and appeared to be unhurt. He took a seat behind the lectern and left the stage when the ceremony concluded soon afterward, jogging to his motorcade.

Ben LaBolt, the White House communications director, said on Twitter that Mr. Biden was "fine." Press secretary Karine Jean-Pierre echoed that statement, saying he feels "totally fine" and boarded Air Force One with "a big smile."

Mr. Biden addressed the 921 graduates earlier in the ceremony for about 30 minutes, hailing the strength of the U.S. military and touching on several foreign policy topics, including Ukraine, China and NATO, media reported.

On his way into the White House after flying back to Washington, the president ignored reporters' questions except to joke, referring to his fall that "I got sandbagged!"