President Trump said Thursday that he had decided to remove FBI Director James Comey long before his deputy attorney general recommended he do so, and said Comey had informed him that he was not under investigation during a previously unreported private dinner.

"What I did is, I was going to fire Comey. My decision," Trump told NBC's Lester Holt just two days after dismissing the FBI director. Previously, his White House had suggested that it was the recommendation of Deputy Attorney General Rod Rosenstein that prompted Comey's termination.

"Oh, I was going to fire regardless of recommendation," Trump said.

The president criticized Comey's performance in the high-profile Hillary Clinton email case, during which he announced the details of the investigation before declaring that "no reasonable prosecutor" would recommend charges for activity he had described as "extremely careless."

"He's a showboat. He's a grandstander," Trump said of Comey. "You take a look at the FBI a year ago, it was in virtual turmoil."

Trump also explained why he had included, in his dismissal letter Tuesday to Comey, a line thanking the FBI director for informing him on three separate occasions that he was not under criminal investigation. White House deputy press secretary Sarah Sanders had refused on Wednesday to elaborate on what the president had meant.

"I had a dinner with him," Trump said. "He said it once at dinner and then he said it twice during phone calls."

Trump noted he had pressed Comey directly on whether he was the subject of a criminal investigation related to Russia's attempted interference in the 2016 presidential race.

"I actually asked him, yes," Trump said. "He told me that [I was not under investigation]."

The president clarified that when Comey had informed Trump that the FBI was not investigating him, he was referring to "me personally."

"I'm not talking about campaigns," Trump said.

Weeks before his termination, Comey had informed lawmakers that the FBI was looking into allegations that the Trump campaign colluded with Russians to steal and publish Democrats' emails during the presidential race.