Calls for Biden to step aside grow louder

US President Joe Biden is facing a brutal reckoning after he repeatedly stumbled during Thursday night's debate, with some Democrats calling for him to step aside ahead of the November election.

Biden was incapable of swatting down a stream of falsehoods from Donald Trump, who appeared calm and energised in contrast to a bewildered looking President who struggled to maintain thoughts.

"This was like a champion boxer who gets in the ring past his prime and needs his corner to throw in the towel," said a Democratic lawmaker, adding that he meant Biden should exit the race.

It's "time to talk about an open convention and a new Democratic nominee," said a second Democratic lawmaker who has been a solid Biden supporter.

The New York Times editorial board, which endorsed Biden in 2020, called on him to drop out of the race to give the Democratic Party a better chance of beating Trump by picking another candidate. "The greatest public service Mr Biden can now perform is to announce that he will not continue to run for re-election," the editorial said.

Democratic campaign spokesperson Michael Tyler said there were no conversations taking place about that possibility. "We'd rather have one bad night than a candidate with a bad vision for where he wants to take the country," he told reporters aboard Air Force One.

Biden, however, said on Friday evening he intended to defeat Trump in the November presidential election, giving no sign he would consider dropping out of the race.

"I know I'm not a young man, to state the obvious," an ebullient Biden said at a rally. "I don't walk as easy as I used to, I don't speak as smoothly as I used to, I don't debate as well as I used to," he said, as the crowd chanted "four more years."

"I would not be running again if I didn't believe with all my heart and soul that I could do this job. The stakes are too high," Biden said.

The campaign held an "all hands on deck" meeting on Friday afternoon to reassure staffers that Biden was not dropping out of the race, according to two people familiar with the meeting.

Though Trump, 78, put forward a series of falsehoods throughout the debate, the focus afterward was squarely on Biden, especially among Democrats.

Hakeem Jeffries, the Democratic Party leader in the US House of Representatives, avoided answering directly when asked whether he still had faith in Biden's candidacy, reports Reuters.

Some other Democrats likewise demurred when asked if Biden should stay in the race. "That's the president's decision," Democratic Senator Jack Reed told a local TV station in Rhode Island.

But several of the party's most senior figures, including former presidents Bill Clinton and Barack Obama, said they were sticking with Biden.

"Bad debate nights happen. Trust me, I know. But this election is still a choice between someone who has fought for ordinary folks his entire life and somebody who only cares about himself," former Democratic President Barack Obama wrote on X.