Joe Biden has tense exchange with voter at town hall: 'You're a damn liar, man' (VIDEO)

Former Vice President Joe Biden had a tense exchange with a voter at a town hall event in New Hampton, Iowa on Thursday.

Things started off with a few laughs but quickly got heated when the 83-year-old unnamed voter criticized Biden for his son's involvement in Ukraine. He also suggested Biden might not be fit for the presidency due to his age.

Voter: (This whole thing with Trump)...but you on the other hand sent your son over there, getting a job to work at a gas company that he had no experience having. So, you're selling access to the president just like he is.

Biden: You're a damn liar, man. That's not true. No one has ever said that.

One of Biden's aides was going to take the man's mic away, but Biden insisted to "let him go."

Biden went on: Look, the reason I'm running is because I've been around a long time, and I know more than most people know, and I can get things done. And, if you want to check my shape, let's do push-ups together. Let's run. Let's do whatever you want to do. No one has said my son has done anything wrong.

Voter: I didn't say ya'll did anything wrong....

Biden: You just said I sent my son to work at an oil company...get your words straight, Jack.

Trump and his cronies are trying to paint this as Biden exploding on a retired farmer.

Biden did use the words "jack," "fat," and "too old," to describe the man in the exchange, but it was a hostile encounter.

Earlier in the day former Secretary of State John Kerry handed Biden his endorsement for president.

“I believe Joe Biden is the president our country desperately needs right now, not because I’ve known Joe so long, but because I know Joe so well,” Mr. Kerry said in a statement. “I’ve never before seen the world more in need of someone who on Day 1 can begin the incredibly hard work of putting back together the world Donald Trump has smashed apart.”