The White House says the wind is to blame for President Joe Biden's triple fall on the stairs of Air Force One today.
Video showing Biden stumbling three times and then falling while boarding the presidential plane has prompted fresh questions about his health.
It was not immediately clear what tripped Biden up the first time, but shortly after recovering he fell twice more before dusting himself off. Security officials watched with concern from the ground.
The president recovered to give a salute at the top of the stairs before departing to meet Asian-American community leaders in the wake of the massage parlour massacre in Atlanta, Georgia.
On the plane, White House Deputy Press Secretary Karine Jean-Pierre told reporters Biden was "100 per cent fine".
She also said: "It's pretty windy outside. It's very windy. I almost fell coming up the steps myself."
White House communications director Kate Bedingfield later posted a tweet reassuring the public that Biden was unhurt after his "misstep on the stairs".
"I know folks have seen that President Biden slipped on his way up the stairs to AF1, but I'm happy to report that he is just fine and did not even require any attention from the medical team who travels with him," Bedingfield said.
Once he landed in Atlanta, Biden remained on board Air Force One until Vice-President Kamala Harris joined him. The White House said they met to discuss the day's agenda.
Harris then disembarked with Biden, walking behind him as he slowly descended the stairs.
Biden, 78, is the oldest person to assume the US presidency. He has said he uses a Peloton bike to keep fit and often makes a point of jogging.
However, questions have been raised about Biden's mental and physical acumen. The president on Thursday accidentally called his Vice-President "President Harris".
Throughout the election campaign he slurred his words, mispronounced words and misidentified people, such as calling his wife Jill his sister.
A senior pro-Kremlin politician in Russia accused Biden of having dementia on Thursday, striking back after the US president called his counterpart Vladimir Putin a "killer".
Republican detractors have long claimed the president is suffering from senility.
"I remember the press bashing Trump for touching the rail once," tweeted a gleeful Donald Trump Jnr, sharing the clip of the incident.
"Biden falls repeatedly but I'm sure he's the picture of health. No wonder all our enemies are pouncing simultaneously and mocking him publicly."
The president's latest medical report showed no signs of any degenerative disease.
Biden survived two brain aneurysms in the late 1980s — one did not rupture. And while the condition was later complicated by deep vein thrombosis and pulmonary embolism, his doctor at the time stated there was no serious threat to his health.
Despite concerns over his health, a new Reuters/Ipsos poll shows the number of Americans who approve of Biden has grown steadily since he took office, driven by concrete steps his administration has taken to address the public health and economic crisis caused by the coronavirus pandemic.
The March 17-18 national opinion poll found that 59 per cent of adults in the US approved of Biden's overall job performance, while 35 per cent disapproved and 6 per cent said they were not sure.
The number of adults who approve of Biden is up by about 4 percentage points since a poll that ran in late January, and the increase is largely due to a rise in Biden's popularity among independents.
Additional reporting: Daily Telegraph