While President Joe Biden is adamant about running for another term in office, one figure who is very familiar with the president is expressing doubts.  

According to The Hill, Biden biographer Franklin Foer said during a Sunday appearance on "Meet the Press" that it "wouldn’t be a total shock" if the president were to drop out of the race.

"It wouldn’t be a total surprise"

"I would say it would, it would be a surprise to me. But it wouldn’t be a total surprise," Foer admitted to host Chuck Todd.

WATCH: It would not be a "total shock" if Biden decided not to seek re-election at the end of 2023, says @FranklinFoer, who wrote a book about the president’s first term.

"When he talks about his life ... he always talks about [how] he can't say where fate goes. pic.twitter.com/Ner7eaE3cx

— Meet the Press (@MeetThePress) September 3, 2023

"When he talks about his life, he uses this word, fate, constantly. Joe Biden is a very religious guy, and fate is a word loaded with religious meaning," the author continued.

"And he always talks about, 'He can’t say where fate goes.' And so I always, when I hear that, to me, it’s the ellipses in the sentence when he’s talking about his own future," Foer added.

Biographer "can’t predict how the next couple of years will age Joe Biden"

"I think what my book does is shows that he is somebody who, for whom — he’s buried in details," Foer said, referencing his biography Biden titled, "The Last Politician."

"It doesn’t take Bob Woodward to understand that Joe Biden is old, and I’m not a gerontologist and I can’t predict how the next couple of years will age Joe Biden," he stressed.

"He’s somebody who is very technocratic, really obsessed with the intricacies of policy. He’s a very activist president in that he micromanages a lot of the dealings in the White House," Foer claimed.

There have long been concerns about Biden's age and fitness for office, and the results of a poll carried out last month by NORC Center for Public Affairs Research suggests they aren't just confined to Republicans.

Poll finds 77% of Americans think Biden is too old for another term

Conducted between August 10 and August 14, the survey found that 77% of Americans believe Biden "is too old to effectively serve another 4-year term as president."

"77 percent in new poll say Biden is too old to be effective if reelected" (@TheHillOpinion) https://t.co/ZqvLInFXxm pic.twitter.com/4pYpQfNXgU

— The Hill (@thehill) August 28, 2023

That figure included 74% of independent voters and even 69% of Democrats. Interestingly, only 51% of voters expressed the same view of former President Donald Trump.

Just 28% of Republicans and 48% of independent voters say Trump is too old for another White House term. That number jumps to 71% when the question is put to Democrats.