Speaking with Fox Business host Maria Bartiromo, Trump said Comey "was very, very good" to Clinton, adding that she would be "going to trial" if he were not.
It was part of a lengthy exchange that began when Bartiromo asked Trump whether it was a mistake to not ask Comey to step down as director of the FBI.
Comey confirmed last month that the FBI was looking into potential collusion between Trump associates and Russian government officials aimed at influencing last year's presidential election, adding that the FBI investigation began in late July.
"Is it too late now to ask him to step down?" Bartiromo asked.
"No, it's not too late, but, you know, I have confidence in him," Trump responded. "We'll see what happens. You know, it's going to be interesting. But, you know, we have to just — look, I have so many people that want to come into this administration. They're so excited about this administration and what's happening — bankers, law enforcement — everybody wants to come into this administration."
"Don't forget, when Jim Comey came out, he saved Hillary Clinton," Trump added, referring to the public statement Comey made in July that the FBI did not believe it was appropriate to file charges for Clinton's use of a private email server while she was secretary of state. "People don't realize that. He saved her life, because — I call it Comey won. And I joke about it a little bit."
In describing Comey's reading of what the FBI was looking into regarding Clinton's use of the server, Trump claimed it was clear Clinton "was guilty on every charge."
"And then he said, she was essentially OK," he said. "But he — she wasn't OK, because she was guilty on every charge. And then you had two and then you had three. But Hillary Clinton won — or Comey won. She was guilty on every charge."
"Director Comey was very, very good to Hillary Clinton — that I can tell you," the president later added. "If he weren't, she would be, right now, going to trial."
Asked by Bartiromo whether he would "push that," Trump said he didn't "want to talk about that."