Former FBI Director James Comey. AP Photo/Alex Brandon

Former FBI director James Comey is willing to testify before the Senate, but he will only do so in public, a close associate told The New York Times.

Comey has made no public statements since being fired, and he declined an invitation to testify before the Senate Intelligence Committee in a closed door session, ranking member Mark Warner told MSNBC on Friday.

Comey's firing ignited a firestorm in Washington and has prompted speculation over whether Trump's decision hinged on his apparent anger at the FBI's probe into the Trump campaign's potential collusion with Russia during the 2016 election.

Though the White House initially said that Comey's removal had nothing to do with the Russia investigation, Trump later told NBC News' Lester Holt that the investigation was a factor in his decision.

"In fact, when I decided to just do it, I said to myself, I said, 'You know, this Russia thing with Trump and Russia is a made up story, it’s an excuse by the Democrats for having lost an election that they should have won,'" Trump told Holt during the interview.

Since firing Comey, Trump has raged at Democrats and other critics who have blasted him for firing the man who was spearheading an investigation centered around him. He also sent out a tweet in which he appeared to threaten Comey by releasing recordings of their conversations.

"James Comey better hope that there are no "tapes" of our conversations before he starts leaking to the press!" Trump tweeted on Friday.

A source close to Comey told NBC News that Comey "hopes there are tapes. That would be perfect."