Former Trump adviser Roger Stone said Thursday he’s “very anxious” to testify before the House and Senate panels investigating Russia’s ties to the Trump campaign.

“I myself am very anxious to testify before the House and Senate committees in public. I don’t need a subpoena. I don’t need immunity. I’m going to give them whatever documents they requested, although I believe I’ve been under surveillance so they probably already have them anyway,” he said on CNN.

Mr. Stone is a person of interest in the Russia investigation partly because his tweets about Hillary Clinton’s campaign Chairman John Podesta prior to the WikiLeaks release of private emails, which indicate Mr. Stone may have known the leaks were coming. He denies this, explaining that he was referring to the business deals Mr. Podesta had with the Clintons that he felt were problematic and not the WikiLeaks release.

Mr. Stone also said he agreed with Mr. Trump’s decision to fire former FBI Director James B. Comey, but said he would’ve fired him sooner.

“I would’ve fired him from day one,” he said.

Mr. Stone said the agency had become too politicized and needed a change in leadership.

“Mr. Comey has worn out his credibility,” he said. “My sources in the bureau, mostly at the agent level, are pretty happy. They believe the agency had been pretty politicized under James Comey.”