Former CIA Director John Brennan testified before the House Intelligence Committee on May 23.
Former CIA Director John Brennan testified before the House Intelligence Committee on May 23.

In remarks before the House Intelligence Committee on Tuesday, John Brennan, former director of the CIA, said he suspected that associates in Donald Trump's campaign staff worked with Russian authorities in influencing January's presidential election.

Brennan told the committee that he became convinced last summer that Russia was "very aggressive" in its efforts to interfere with the campaign.

"I encountered and am aware of information and intelligence that revealed contacts and interactions between Russian officials and U.S. persons involved in the Trump campaign that I was concerned about because of known Russian efforts to suborn such individuals," he told the committee, one of a handful of congressional committees now looking into Russian involvement in the 2016 election. "And it raised questions in my mind again whether or not the Russians were able to gain the cooperation of those individuals."

His comments are the clearest testimony by a U.S. official of involvement of Russian operatives with the Trump campaign and likely will weaken President Trump's efforts to dismiss the allegations as a "witch hunt."

Although he could offer no conclusive evidence and couched his remarks in conditional terms, saying he had "unresolved questions in my mind" regarding the involvement of Russia in efforts to affect the U.S. election, he said he believed the ongoing investigation by the FBI into possible collaboration between Russia and the Trump campaign is “certainly well founded.”

He made it clear that he could not opine on whether the intelligence his agency gathered amounted to collusion – as he explained that the CIA merely gathers intel and does not investigate criminal matters – but he did say he passed along evidence assembled by his agency to the FBI.

“I know that there was a sufficient basis of information and intelligence that required further investigation by the bureau to determine whether or not U.S. persons were actively conspiring and colluding with Russian officials," Brennan informed the committee.

He also said he was "worried by a number of the contacts that the Russians had with U.S. persons.”

In a statement issued on Tuesday, a spokesperson at the White House responded that Brennan's testimony cleared the Trump campaign: "despite a year of investigation, there is still no evidence of any Russia-Trump campaign collusion."

Further, Brennan also criticized President Trump's alleged sharing of classified intelligence in a meeting at the White House with Russia's foreign minister and ambassador to the U.S. If what's been reported about the incident is true, he said, the president overstepped "protocols" in sharing the information.

Brennan was scheduled to speak in a closed door session following his public appearance before the House Intelligence Committee.

Meanwhile, at a Senate Armed Services Committee hearing also on Tuesday, Dan Coats, Director of National Intelligence, opted out of commenting on a report in The Washington Post that asserted that Trump requested that he deny evidence of Russian involvement in the election.

“I don't feel it's appropriate to characterize discussions and conversations with the president,” Coats told the committee.

However, he did say that should he be questioned by the Senate Intelligence Committee, he "certainly will provide them with what I know and what I don't know.”