Conan O'Brien, Stephen Colbert and Jimmy Fallon. Picture: Screengrab/Facebook

Los Angeles — Three late-night TV hosts have teamed up for a rare joint opening to respond to President Donald Trump slamming comedians at a rally in South Carolina on Tuesday. 

Trump called Jimmy Fallon "a lost soul", Stephen Colbert a "lowlife" and Jimmy Kimmel "terrible".

WATCH: Trump hurls insults at late-night hosts Colbert, Kimmel, Fallon

Colbert’s “The Late Show” on CBS and Fallon’s “The Tonight Show” on NBC began Tuesday with the taped segment in which the hosts video chat about comments Trump made about them Monday.

Fallon says, "Hey, lowlife." Colbert responds, "Hey, lost soul." Fallon says he heard Trump said they are "all no-talent, lowlifes, lost souls."

Colbert says that describes TBS host Conan O'Brien, who appears while shaving and says he didn't realise Trump had become president.

O'Brien cautions the hosts to be civil. He says, "If we're not careful, this could start to get ugly."

Colbert and Fallon agree to meet at the restaurant that denied service to Trump's press secretary.