VIDEO: Joe Biden stumbles on staircase yet again

Eighty-year-old US President Joe Biden again stumbled as he made his way up the steps to board Air Force One on Thursday — even as he used a less challenging short staircase.

Biden, the oldest politician to hold the president's office, was roughly halfway up the 14-step staircase connected to the plan in Finland's Helsinki when he misstepped.

As soon as that happened, Biden quickly recovered and went up to the plan's entrance.

Biden has been using smaller staircases to board the presidential plane since his hard fall last month in Colorado when he tripped over a sandbag.

The latest stumble is the fourth time that the president has taken a misstep while boarding Air Force One. 

Biden's stumble comes days after some questioned why a "watch your step" sign was spotted on the stairs leading up to Air Force One during Biden's arrival in the UK on Sunday night.

The oldest-serving US president has repeatedly faced criticism over his age and past incidents when he tripped and fell.

The president turns 81 in November, and if he wins the reelection in 2024, he will be 82 at the beginning of his second term.

It's not uncommon for presidents to suffer embarrassing moments during their time in office.

Donald Trump, Biden's predecessor, has been scrutinised when he looked slow and unsteady in public appearances. And he is three years younger than him.