President Donald Trump responded Thursday to former Vice President Joe Biden's latest taunt.

Trump suggested Biden would "go down fast and hard" in a fight, "crying all the way."

Biden earlier this week said he would have "beat the hell" out of Trump if the two had been in school together.

Biden and Trump have gone back and forth over an imagined showdown for about a year and a half.

Biden's latest remarks came while he was discussing crude remarks Trump had made about women.

President Donald Trump has responded to former Vice President Joe Biden's latest taunt that he would "beat the hell" out of Trump if the two had gone to school together, saying Biden was weak and would lose 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," Trump tweeted Thursday morning. "He doesn't know me, but he would go down fast and hard, crying all the way. Don't threaten people Joe!"

For about a year and a half, Biden and Trump have gone back and forth suggesting they could beat the other in a fight.

The latest incident began Wednesday, when Biden, speaking at a rally at the University of Miami against sexual assault, brought up the 2005 "Access Hollywood" tape wherein Trump boasted about sexually assaulting women.

"A guy who ended up becoming our national leader said, 'I can grab a woman anywhere and she likes it,'" Biden 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.'"

Biden is said to be considering running for president in 2020 against Trump.

While it's illegal to threaten to harm the president, Biden framed his proposal to beat up Trump as a hypothetical situation taking place in the past. It's unclear whether legal action could be taken against Biden.