Don Lemon revealed Tuesday night that President Donald Trump once inferred Lemon was racist, and unable to be an impartial journalist because he’s black.

“The last time I interviewed Donald Trump, before he ran for office, was the night that Osama Bin Laden was killed,” Lemon explained to Wolf Blitzer during CNN’s The Situation Room. “It was before he was killed and we had a row about the birther issue.”

“He vowed that he would never do an interview with me because he said I was racist, because I challenged him on an in-factual statement, a lie.”

“[Trump said] you’re a racist?” CNN talking head Dana Bash asked.

“That I was racist because of the way that I challenged him,” Lemon confirmed. “Much in the way that he thought that I can’t be unbiased about an issue concerning race, like Judge Curiel, because I’m African-American. So he accused me of being racist.”

Lemon’s story comes on the heels of a tweet that Trump sent out last week regarding an interview Lemon conducted with basketball player and philanthropist LeBron James.

During the interview, Lemon asked James what he would say to the president if he was sitting across from him, and James responded, “I would never sit across from him,” then adding, “I’d sit across from Barack though.”

Trump responded on Twitter, “Lebron James was just interviewed by the dumbest man on television, Don Lemon. He made Lebron look smart, which isn’t easy to do. I like Mike!”

In a segment earlier this week, Lemon ripped Trump’s response. “I would just to like note that referring to African-Americans as dumb, remember this is America, referring to African-Americans as dumb is one of the oldest canards of America’s racist past and present, that black people are of inferior intelligence.”

Lemon then highlighted a tweet from CNN’S Keith Boykin that featured 12 statements Trump has made about people of color, mostly African-Americans. The 13th statement on the list wasn’t about people of color, but a reminder of what Trump said regarding the neo-Nazis who gathered in Charlottesville, Virginia one year ago.

“Nazis: very fine people.”