Another Democratic lawmaker has weighed in on President Biden's mental fortitude and whether he is capable of holding office for a second term.

Rep. James Clyburn, D-S.C., admitted to NBC in a Friday interview that Biden is not the same person as he was four years ago, but asserted that he is still "mentally" fit with one of the "best minds" he's ever worked with.

"You’re traveling with him next week, you’ve spent more time with the president than just about anybody else in the House, is this the same Joe Biden that we saw two years ago?" interviewer Craig Melvin asked Clyburn, who had endorsed Biden in the 2020 presidential race. 

DEFIANT BIDEN SAYS HE'S 'DETERMINED ON RUNNING,' AS NEW POLL AFTER PRESSER SHOWS SLIGHT LEAD OVER TRUMP

Biden press conference

Biden held a news conference with members of the White House press corps during the NATO Summit in Washington, D.C., on July 11, 2024.  (Graeme Sloan/Bloomberg via Getty Images)

"Well, look, I grew up in..." Clyburn started to say before he was asked again, "Is it the same Joe Biden?" 

"No," Clyburn said emphatically, adding that, "I’m not the same Jim Clyburn that I was four years ago." 

Clyburn later said he doesn’t think Biden, physically, is the same as he was during the last presidential election cycle. 

TOP DEMOCRAT ON THE HOUSE INTEL COMMITTEE RESPONDS TO BIDEN'S PRESS CONFERENCE

Rep. James Clyburn

Rep. James Clyburn, D-S.C., talks with reporters in the U.S. Capitol following the presidential debate between President Joe Biden and former President Donald Trump. (Tom Williams/CQ-Roll Call, Inc via Getty Images)

"Mentally, I do think so," Clyburn declared. "He is still grasping what this country is all about." 

"He has one of the best minds that I have ever been around. The people who've been around him will tell you that, and so I would hope that we will focus on the substance of this man, rather than these sometimes, misspoken words and phrases, and how he has run this country."

Biden faced a wave of mockery online Thursday after he introduced Ukrainian President Volodymyr Zelenskyy as "President Putin" ahead of his press conference.

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President Joe Biden and Ukraine President Volodymyr Zelenskyy

President Joe Biden and Ukrainian President Volodymyr Zelenskyy participate in the launching of the Ukraine Compact at the 2024 NATO Summit in Washington, DC. Biden accidentally introduced Zelenskyy as "Putin" — the president of Russia responsible for the invasion of his home country. (Kevin Dietsch/Getty Images)

During the conference, Biden also referred to his Republican opponent, former President Donald Trump, as his vice-president.

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Biden was peppered with questions from reporters who pressed him on whether he would step aside amid mounting pressure from members within his own party following his disastrous debate performance last month.

The president dismissed the notion he's "slowing down" and insisted he was "determined on running" in this year's election.

Fox News Digital's Greg Norman and Brooke Singman contributed to this report. 

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