Facing persistent questions about his ability to serve, US President Joe Biden said he’s willing to relinquish power to Vice President Kamala Harris if he wins a second term but is unable to complete it for health reasons - while discounting the likelihood of that scenario.

“Only if I was told that there was some medical condition that I had, and that’s not the case,” Biden said when asked in a BET interview broadcast on Wednesday if he would consider being a transitional figure, then turn over the presidency to Harris within two years.

Biden, 81, acknowledged that questions about his age are “a legitimate thing to raise”. But he defended his ability to lead the nation and expressed confidence he could serve another four years in the White House. 

The president would be 86 years old at the end of a second term.

“I’m only three years older than Trump, OK. And I think I’m in a little better physical shape than he is,” Biden said. “As long as I can demonstrate that it’s not affecting my ability to compete, my ability to get things done, my ability to literally lead the world.”

Pressed on whether he would reconsider his service on a year-on-year basis, Biden said, “As a practical matter, yes. But there’s no reason to believe that’s likely to happen.”

Biden has embarked on a furious effort to reassure the public of his mental acuity following his disastrous performance in a June 27 debate with Trump. Yet the onslaught of interviews, campaign events and strategy memos has done little to assuage fellow Democrats’ persistent doubts about his ability to defeat Donald Trump. 

Earlier in the interview, Biden said he would also be willing reconsider his determination to run for re-election if he had a medical condition that emerged.

The president was dealt several fresh blows on Wednesday. He tested positive for the coronavirus, forcing him to cancel a speech to a major Latino advocacy group. 

The diagnosis was announced after California Representative Adam Schiff became the most prominent Democrat to publicly call for Biden to withdraw from the race. The top US House and Senate Democrats in private conversations warned Biden about the continued risks his candidacy poses to the party’s efforts to win control of Congress, ABC News and The Washington Post reported.

Even as Biden repeatedly vows to stay in the race, he has recently made a point to publicly declare confidence in Harris as questions about his health have touched off a debate over whether the vice president would be the most viable replacement if he steps aside. 

  - Bloomberg