Watch: Donald Trump and Joe Biden squabble about who's the best golfer in 'car crash' exchange

Donald Trump accused a raspy Joe Biden of lying about his golf handicap as the first US election debate descended into farce.

Despite speaking about a large range of issues, ranging from Trump’s recent felony conviction to Mr Biden evoking his son, Beau, who served in Iraq before dying of brain cancer, one of the most memorable moments of the 90-minute debate on CNN was a clash about golf handicaps.

In one bizarre exchange during the in-depth debate Biden took aim at Trump for lying about his height before challenging him to play golf.

Answering a question about his fitness, Trump, who would be 82 at the end of a second term, bragged that he was in “very good shape” and had recently won two championships at one of his golf courses.

“To do that, you have to be quite smart and you have to be able to hit the ball a long way,” Trump said.

Biden, he said, “can’t hit a ball 50 yards” before the President touted his his own golf abilities.

“I’d be happy to have a driving contest with him,” he said.

“I got my handicap when I was Vice President down to a six.”

“By the way I told you before, I’m happy to play golf with you if you can carry your own bag. Think you can do it?”

In response Trump said: “That’s the biggest lie, that he is a six handicap, of all.”

Biden then appeared to contradict himself by adding: “I was an eight handicap.”

Before Trump said: “I’ve seen your swing, I know your swing. Let’s not act about children though.”

Biden’s handicap is listed on the United State Golf Association’s website as 6.7, with the last update in July 2018. Trump’s handicap, last updated in June 2021, is listed as 2.5.

In one of their first exchanges in four years Biden tried to take aim at the former Republican President on a range of issues but ultimately raised concerns that he is too old for a second term in the White House.

The 81-year-old tore into Trump, bringing up the former president’s recent conviction, insults of war veterans and even his weight.

Trump countered by leaning into falsehoods about the economy, illegal immigration and his role in the January 6, 2021, Capitol riots.

Biden's uneven performance, particularly early in the debate, sparked fresh calls for the Democrat to step aside as members of his party fear he can not stop Trump returning to the White House.

"I think the panic had set in," said David Axelrod, a longtime advisor to former President Barack Obama on CNN, immediately after the debate about Biden's performance.

"And I think you're going to hear discussions that, I don't know will lead to anything, but there are going to be discussions about whether he should continue."

Vice President Kamala Harris, speaking on CNN afterward, sought to defend the president's performance while acknowledging the criticism.

"There was a slow start, but there was a strong finish," she said.

Asked about his performance in the debate, Mr Biden told reporters early on Friday that "I think we did well," but said he has a "sore throat."

Pressed about Democratic concerns about his performance and whether he should consider stepping aside, Mr Biden said, "No, it's hard to debate a liar."