President Trump said Tuesday that he regrets not firing James B. Comey as FBI director sooner, asserting that he should have done so while still a candidate for president -- an option that was not actually available to him.

“If I did one mistake with Comey, I should have fired him before I got here,” Trump said in an interview with Hill.TV. “I should have fired him right after the convention, say I don’t want that guy. Or at least fired him the first day on the job. ... I would have been better off firing him or putting out a statement that I don’t want him there when I get there.”

Trump fired Comey in May 2017, citing concerns about the way he handled the investigation in Hillary Clinton’s use of a personal email server while secretary of state. He later suggested that the FBI investigation into Russian interference in the 2016 election was a factor.

Trump’s firing of Comey has been under scrutiny by special counsel Robert S. Mueller III as his team probes whether Trump obstructed the Russia investigation.

The FBI director enjoys a unique status in the Justice Department. The person picked for the job is appointed to a 10-year term, which is designed to insulate whoever is in the position from politics. That is different even than the attorney general, the country’s top law enforcement official.

While the president can remove the FBI director, doing so is extremely rare and comes with significant political cost. Before Comey, only one FBI director had been removed by the president since 1972 — William Sessions, who was fired by President Bill Clinton in the 1990s over allegations of ethics violations.

Trump repeatedly lashed out at Comey this spring as the former FBI director was promoting a tell-all book that describes Trump’s presidency as a “forest fire” and portrays the president as an ego-driven congenital liar.

In an April tweet, for instance, Trump called Comey a “weak and untruthful slime ball” who deserved to be fired “for the terrible job he did.”

Trump, however, has not always taken such a negative view of Comey.

During the 2016 campaign, Trump praised Comey after he announced he was reopening the investigation into Clinton’s email practices.

“It took a lot of guts. I really disagreed with him. I was not his fan,” Trump said of Comey at a late-October rally in Michigan. “I tell you what, what he did, he brought back his reputation. He brought it back. He's got to hang tough. A lot of people want him to do the wrong thing. What he did was the right thing.”

In a November 2016 interview on CBS’s “60 Minutes” shortly after his election, Trump said of Comey: “I respect him a lot. I respect the FBI a lot.”

In late January 2017, on his second full day in office, Trump recognized Comey at an event for law enforcement officers, motioning for him to come across the room. Comey shook Trump’s hand, and Trump patted Comey on the back.