Gavin Newsom will run for president in 2024 if Joe Biden bows out – a possibility seeming more likely after the president cast doubt on his candidacy in his first sit-down interview in more than 200 days.

The California governor, two individuals with knowledge of his plans say, is 'undeniably, unequivocally' planning to enter the race for the White House if the incumbent isn't in the running for a second term.

'After this midterm election is over, he absolutely is going to announce that he is running for the presidency once Biden announces that he is not running,' a California fundraiser with ties to the Newsom family told The Wrap.

'No ifs, ands or buts. He will run if Biden does not,' they added.

A Los Angeles-based philanthropist connected to the Democratic Party and fundraising for its candidates confirmed Newsom's strong intentions to run.

While defending his fitness for office, Biden refused to say if he would seek another term.

'My intention, as I said to begin with, is that I would run again,' Biden told 60 Minutes host Scott Pelley. 'But it's just an intention.'

'Is it a firm decision that I run again? That remains to be seen,' the president added.

This is the first time Biden has really cast doubt on the potential of running for reelection in 2024 – with his previous comments pointing to every intention of vying for a two-term presidency.

If Biden doesn't run, there are also reports and speculation that Vice President Kamala Harris, once a senator from California, could wade into the presidential race waters. She has insisted repeatedly that she intends to run as Biden's No. 2 for a second term in 2024.

America's oldest president shot down criticisms that he is too old and mentally unfit to be president during his first sit-down interview with the press in more than 200 days.

A series of public gaffes — including videos showing him falling up the stairs to Air Force One and forgetting he already shook Senator Chuck Schumer's hand – have cast doubt on his ability to continue for another four years after a first term.

'Some people think you are unfit for the job,' CBS correspondent Scott Pelley began, 'and when you hear that, I wonder what you think.'

'Watch me,' the president replied. 'Honest to God that's all I think.

'If you think I don't have the energy level or the mental acuity, then you know, that's one thing,' he said. 'It's another thing, you know, just watch and, you know, keep my schedule. Do what I'm doing.'

He continued: 'I respect the fact that people would say, you know, 'You're old.'

'But I think it relates to how much energy you have and whether or not the job you're doing is one consistent with what any person of any age would be able to do.'

If Biden were not to run for office and Newsom put his name in the hat – the California Democrat would have his own set of hurdles to overcome.