WASHINGTON - US President Donald Trump blasted ousted FBI chief James Comey as a "showboat" and "grandstander" on Thursday even as the agency's acting leader contradicted the leader's account that the FBI had been in turmoil before he fired Comey.

In testimony before the Senate Intelligence Committee, acting Federal Bureau of Investigation director Andrew McCabe promised to tell the panel of any White House meddling into the agency's probe into possible collusion between Russia and Trump's presidential campaign.

McCabe testified in place of Comey, who Trump abruptly dismissed as FBI director on Tuesday in an action that has roiled Washington. Democrats have accused the Republican president of trying to foil the FBI's probe into Moscow's actions and many have called for a special prosecutor to look into the matter.

"He's a showboat. He's a grandstander. The FBI has been in turmoil," Trump said in his first interview since firing Comey. "I was going to fire Comey. My decision," Trump said. "I was going to fire regardless of recommendation."

Trump said he never pressured Comey into dropping the FBI probe, adding: "If Russia did anything, I want to know that. Trump said there was no "collusion between me and my campaign and the Russians."

McCabe's testimony contradicted Trump's appraisal of turmoil at the FBI under Comey.

"I can tell you also that Director Comey enjoyed broad support within the FBI and still does to this day," McCabe said.

"I can tell you that I hold Director Comey in the absolute highest regard. I have the highest respect for his considerable abilities and his integrity," McCabe added. "And it has been the greatest privilege and honor of my professional life to work with him."

Trump said he had previously asked Comey whether he was under investigation in the Russia matter, speaking with Comey once over dinner and twice by telephone.

"I said, 'If it's possible, would you let me know, am I under investigation?'" Trump told NBC. "He said, 'You are not under investigation.'"

Comey has neither publicly discussed conversations with Trump nor has he publicly commented on his dismissal.

'Not typical practice'

McCabe testified it was not typical practice to tell a person they are not a target of an investigation.

At the daily White House news conference, spokeswoman Sarah Huckabee Sanders was asked whether it was a conflict of interest for a president to ask the FBI chief such a question. She answered: "No, I don't believe it is."

Trump's contention that he was going to fire Comey regardless of what Attorney General Jeff Sessions and the No. 2 Justice Department official Rod Rosenstein recommended conflicts with earlier explanations from the White House. Spokesman Sean Spicer said on Tuesday that Trump acted based on the recommendation of Sessions and Rosenstein.

The Republican chairman of the Senate panel, Richard Burr, asked McCabe whether he ever heard Comey tell Trump the president was not the subject of investigation. McCabe sidestepped the question, saying he could not comment on an ongoing investigation.

Reuters - Xinhua - Ap