“It wasn’t an automatic decision about running again,” Biden said at a fund-raiser on Wednesday evening at the New York apartment of former Blackstone vice-chairman Tony James, Bloomberg reported.
Biden, 80, also acknowledged questions about his age were “totally legitimate”.
But he said he hopes his experience in government would serve as an advantage.
“But I hope what I’ve been able to bring to this job and will continue to is a little bit of wisdom,” said Biden, who announced his re-election campaign in late April. “I’m not going to walk away from anything that I don’t think is the best thing to do.”
“I think we’ve made some pretty solid decisions,” he added.
An ABC News/Washington Post poll released over the weekend found the US president’s approval rating at just 36 percent, while 68 percent of Americans said he was too old to serve another term.
A Yahoo News/YouGov poll released earlier on Wednesday, though, showed Biden with a slight lead over both former US president Donald Trump and Florida Governor Ron DeSantis – the two leading Republican candidates – in a potential head-to-head match-up.