In 2015, before he was elected president, Trump tweeted: “John Oliver had his people call to ask me to be on his very boring and low rated show. I said ‘NO THANKS’ Waste of time & energy!”

Oliver and Last Week Tonight denied such an invitation was ever extended at the time, but in a new interview with The Hollywood Reporter, the British comedian said Trump’s persuasive rhetoric is so impressive that he even second-guessed whether Trump might have been invited to appear on the program.

“It’s a really discombobulating thing to think, ‘I know you’re wrong, but you are now more confident in your lie than I am in the truth,’” Oliver explained. “So I said to our staff: ‘Please tell me—it’s fine, no one is in any trouble—if you just reached out to do any fact-check that could be construed as an invitation.’ And obviously the answer was no. But it’s dangerous how good he is at lying in a way that you feel like he could pass a lie detector test.”

Oliver added: “And to lie about something so utterly worthless? Lying about being invited on our show is the lowest-stakes lie imaginable. You are just emptying your ego down the toilet.”

In 2017, Oliver turned Trump’s tweet about appearing on the show into fodder for a caustic segment about joining the so-called “Trump Attacked Me on Twitter” Hall of Fame.

Accepting an award, Oliver said in the segment: “‘Waste of time and energy,’ that I will agree with [Trump] on. ‘Very boring,’ that is also accurate.”

But, said Oliver, “‘John Oliver had his people call to ask me to be on his show’—that is a lie.”

“It was very odd to be on the receiving end of a lie that confident from someone that is now president,” added Oliver. “It was a total lie. A meaningless lie. What kind of moron would lie about something this pathetic?”

Oliver, originally from Birmingham, England, has lived and worked in the U.S. since 2006 and finally became a U.S. citizen last December. He told The Hollywood Reporter that his decision to set roots in the U.S. is not an endorsement of the current president, however.

“Everyone in that room [for the naturalization ceremony] is making a commitment that long outlasts the current president,” Oliver said. “You’re vehemently endorsing the idea of America because the idea is still perfect. That’s what was so moving about the ceremony.”