WASHINGTON, United States (AFP) — US President Joe Biden will Thursday give his first press conference since his debate disaster against Donald Trump, in a pressure-cooker moment that could seal the fate of his reelection bid.

The eyes of the world will be on the 81-year-old at a North Atlantic Treaty Organization (NATO) summit as he tries to calm growing calls from his Democratic party to step aside over his age and health.

The White House has dubbed it a “big boy” press conference, and Biden will be under severe pressure to show he can handle what has become a rare unscripted moment in his presidency.

Any missteps by Biden at the 5:30 p.m. event at a Washington DC conference center could turn the trickle of Democrats who have so far urged him to abandon his 2024 election bid into a flood.

The walls closed in further on Wednesday when Hollywood actor and supporter George Clooney called on Biden not to stand, just weeks after holding a glitzy fundraiser for the president.

Party heavyweight and former House speaker Nancy Pelosi also subtly twisted the knife by stopping short of backing Biden, saying only that he should make a decision after the NATO summit.

The first Democratic senator, Peter Welch of Vermont, meanwhile joined at least eight House Democrats in openly urging the man who beat Trump in 2020 not to stand again.

But many Democrats are believed to be waiting to see if Biden pulls off his first solo press conference since November 2023, or whether it will be a repeat of the debate.