Speaking at an anti-sexual assault rally at the University of Miami, Biden ramped up his criticism of the President, taking particular exception to comments Trump made in the leaked 2005 Access Hollywood video during the campaign.

“A guy who ended up becoming our national leader said, ‘I can grab a woman anywhere and she likes it,'” Biden, a long-time advocate of women’s rights, said. “They asked me if I’d like to debate this gentleman, and I said ‘no.’ I said, ‘If we were in high school, I’d take him behind the gym and beat the hell out of him.’ … I’ve been in a lot of locker rooms my whole life. I’m a pretty damn good athlete. Any guy that talked that way was usually the fattest, ugliest S.O.B. in the room.”

The comments come on the heels of Biden calling Trump “a joke” on CNN, adding, “I just marvel over some of the things he says and does.”

Biden has never been shy about criticizing Trump. Last January, he said he had “no freakin’ idea” what Trump would do as president, noting, “It’s like a Rubik’s cube trying to figure this guy out.”

Trump didn’t let Biden’s challenge go unanswered for long. On Thursday, he replied via Twitter, saying he would come out on top in a fight.

Crazy Joe Biden is trying to act like a tough guy. Actually, he is weak, both mentally and physically, and yet he threatens me, for the second time, with physical assault. He doesn’t know me, but he would go down fast and hard, crying all the way. Don’t threaten people Joe!

— Donald J. Trump (@realDonaldTrump) March 22, 2018

Biden, as of Thursday morning, hasn’t responded to Trump’s tweet.