But, if he were to do it again, Colbert would "change a few words," he said during his show Wednesday evening.
"Welcome to 'The Late Show,' I'm your host Stephen Colbert," Colbert greeted his audience. "Still? Am I the host? I'm still the host!"
He then immediately addressed the joke he made about Trump and Russian President Vladimir Putin during his Monday evening show that some critics called homophobic.
"Now, folks, if you saw my monologue Monday, you know that I was a little upset with Donald Trump for insulting a friend of mine," Colbert said. "So, at the end of that monologue, I had a few choice insults for the president in return. I don't regret that."
"I believe he can take care of himself. I have jokes, he has the launch codes," he continued. While I would do it again, I would change a few words that were crueler than they needed to be. "
On Monday evening, Colbert riffed on the fact that Trump abruptly ended an interview with CBS News political director John Dickerson after the journalist asked about Trump's disputed wiretapping claims against former President Barack Obama.
"Mr. Trump, your presidency, I love your presidency; I call it 'Disgrace the Nation,'" Colbert, who calls Dickerson a friend, said Monday. "The only thing your mouth is good for is being Vladimir Putin's c—holster."
The joke was met with backlash from Trump supporters and conservatives, and the #FireColbert hashtag started trending on Twitter.
"Life is short, and anyone who expresses their love for another person in their own way is, to me, an American hero," Colbert said Wednesday.