In response, Mr Biden said that he would seek to moderate his criticism of Trump before he went on to accuse his rival of filling his campaign with inflammatory rhetoric and falsehoods.
“I’m not the guy that said I want to be a dictator on day one. I’m not the guy that refused to accept the outcome of the election,” he said.
“I’m old,” he said. “But I’m only three years older than Trump, number one. And number two, my mental acuity has been pretty damn good.”
And yet, he again faltered under the pressure of a fast-paced interview.
Asked whether he had spoken with Barack Obama, the former president, recently, Mr Biden was unable to answer whether it was after the debate. “I don’t think – I may have, I don’t think so,” he said.