Biden says if Trump challenges his mental state he'll challenge him to a push-up contest

Presidential candidate Joe Biden said he would challenge President Trump to a push-up contest on-air if the commander-in-chief questions his physical or mental faculties on the 2020 debate stage.

Biden appeared on "Morning Joe" for a Tuesday interview with co-host Mika Brzezinski and said he would immediately retaliate if Trump started poking fun at his behavior.

"I would say, come on Donald, come on, man. How many push-ups do you want to do here, pal? I mean jokingly," Biden said.

"You know, come on, run with me, man. it's like I was in a parade in Independence, Missouri. And I always run in parades... and a fellow from Independence who was a Trump supporter said, 'hey sleepy Joe!' I said, come run with me, Jack. Come on man!"

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Biden said he won't stoop to Trump's level to score political points, but also claimed he wouldn't be taking "any guff" off the president either.

"I'm not going to get down in the dirt with him," he said. "That’s the only place he knows how to fight. I’m just going to continue to talk about what he’s doing -- why it’s so damaging to America and as my mother would say, I'm not going to take any guff from him"

Brzezinski asked Biden how he could handle Trump when some people said he couldn't handle political barbs from Sen. Kamala Harris, D-Calif. He claimed he's used to dealing with bullies and is prepared for a bruising campaign if he becomes the Democratic nominee.

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"I’m used to bullies and so my strategy is, just to go out and remember that famous expression my grandpop used to use ... they said to Harry Truman, give them hell Harry. He said no, I'm just going to tell them the truth. They're going to think it's hell," Biden replied.

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"I know it will be an ugly campaign. I know it will be, not an honorable campaign he’ll run, but I’m not backing down at all from him. Very different than turning to someone on a stage who says something so off the wall to me that — and it’s — because I don’t want to attack anyone on the stage. It’s not what I intend to do, but I realize that some have concluded that because I didn’t respond very tough back to [Harris] that — how can I take on Trump. I've never had any trouble taking on anyone from Trump to Putin to XI Jinping or anybody else."