President Joe Biden tripped and fell on stage on Thursday after handing out the last diploma at a graduation ceremony at the US Air Force Academy in Colorado.
The 80-year-old US President quickly got up on one knee, helped by three people, and walked back to his seat unassisted.
As Mr Biden was helped up, he pointed behind him, seeming to indicate what he tripped over.
A White House reporter said Mr Biden appeared to have tripped over a sandbag on the stage.
White House communications director Ben LaBolt said on Twitter that Mr Biden was fine.
“There was a sandbag on stage while he was shaking hands,” he explained.
The fall came after Mr Biden delivered a commencement address to a flag-waving audience, in which he warned graduates they would enter service in an increasingly unstable world, citing challenges from Russia and China.
Mr Biden, the oldest president in US history, is running for re-election in 2024.
Doctors declared him healthy and fit for duty after a physical examination in February.