UPDATE:  (NBC) - President Donald Trump took a jab at Joe Biden on Thursday, blasting the former vice president on Twitter as "weak, both mentally and physically" and vowing that if they actually fought he "would go down fast and hard, crying all the way."

In a scathing early-morning tweet, Trump responded to earlier insults from Biden and wrote that "Crazy Joe Biden is trying to act like a tough guy."

"Don't threaten people Joe!" the president added about the 75-year-old former vice president.

Earlier this week, at a rally at the University of Miami attended by a sexual assault awareness advocacy group, Biden said he would "beat the hell out of" Trump if they had been in high school together and if he heard him demeaning women.

Biden, who was captured making the remarks in a video posted to Facebook, told the audience Trump once said, "'I can grab a woman anywhere and she likes it' and then said, 'I made a mistake.'"

"I've been in a lot of locker rooms my whole life," Biden said. "Any guy that talked that way was usually the fattest, ugliest S.O.B. in the room."

His comments were in reference to 2005 footage from "Access Hollywood" showing Trump bragging about crude and degrading behavior toward women. Trump later apologized for the comments, calling his remarks "locker room talk."

Biden, for his part, had made a similar remark in response to the video at least once before.

He said at a 2016 campaign rally that if he and Trump "were in high school… could take him behind the gym."

PREVIOUS STORY: MIAMI (AP) - Former Vice President Joe Biden says he would "beat the hell" out of President Donald Trump if they were in high school together and Trump disrespected women.

The Democrat spoke Tuesday at an anti-sexual assault rally at the University of Miami.

"A guy who ended up becoming our national leader said, 'I can grab a woman anywhere and she likes it,'" Biden says. "If we were in high school, I'd take him behind the gym and beat the hell out of him."

Biden says any guy who disrespected women was "usually the fattest, ugliest S.O.B. in the room."

The school's "It's on Us" rally sought to change on-campus culture surrounding sexual assault.

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