US President Joe Biden called on Friday his debate performance against Donald Trump on June 27 "a bad episode," as the president continued attempts to reassure skeptical Democrats following the critical debate.

In his first TV interview since the debate, Biden suggested it was a one-time occurrence because he was exhausted due to a heavy cold and lingering jetlag.

What did Biden say about the debate?

Biden told ABC's George Stephanopoulos that he had a "bad night" the evening of the debate, according to a clip released ahead of the interview. He added that there was "no indication of any serious condition."

He took full responsibility for his poor debate performance, saying his much criticized showing was "nobody's fault but mine."

"I didn't listen to my instincts in terms of preparing," Biden said.

"I was sick, I was feeling terrible," he added. "We were trying to figure out what's wrong. They did a test to see whether or not I had some infection, you know, a virus. I didn't. I just had a really bad cold."

Biden says he is in good shape

In an interview, Biden refused to seek an independent medical evaluation to prove he's fit to serve another term, saying the presidency is "a cognitive test every single day."

The 81-year-old US president said he is "still in good shape," dismissing questions about his age. According to Biden, he has an "ongoing assessment" by his personal doctors and they "don't hesitate to tell me" if something is wrong.

When asked if his staying in the race against Trump could put Democrats at risk of holding the White House, Biden said: "I don't think anybody's more qualified to be president or win this race than me."

He added that he would only leave the campaign "if the Lord Almighty comes out and tells me that I might do that."

Democrats unsure about Biden's prospects

The interview comes at a time when Democrats are concerned about whether Joe Biden can serve another four years and whether he can defeat Republican Donald Trump in November after his stumbling debate performance on June 27.

During the debate, Biden spoke with a raspy voice. He repeatedly got caught up in his phrasing and failed to finish sentences.

There has been growing pressure from within for Biden to step aside as the Democratic nominee for president in 2024. On Friday, however, Biden reiterated that he intends to continue running.

Appearing at a campaign rally in Madison, Wisconsin, the president declared in a speech, "I'm staying in the race. I'll beat Donald Trump."

dh/rmt (AP, AFP, dpa, Reuters)