"There was no evidence that rose to that level, at that time, that found its way in to the intelligence community assessment, which we had pretty high confidence in," the former director of national intelligence said of collusion between Trump campaign aides and Russians, referring also to the US intelligence assessment that Russia tried to influence the presidential election in favor of Trump. "That's not to say there wasn't evidence, but not that met that threshold."
When asked whether the FBI's Russia investigation is fake news, or a "witch hunt," as Trump called it this morning in another tweet, Clapper told MSNBC on Friday: "I don't believe it is."
"But that's kind of irrelevant," he continued. "I think what needs to happen here is to clear this cloud, a cloud that's hanging over the administration, over the President, over the White House. It would be in everyone's best interest to get to the bottom of this, and for the country. Otherwise this is going to continue to linger as a dark cloud, in my opinion, over this administration."
Clapper's remarks come after Trump tweeted that Clapper had said there is no collusion between Trump's 2016 election campaign and Russia.
"When James Clapper himself, and virtually everyone else with knowledge of the witch hunt, says there is no collusion, when does it end?" Trump tweeted.
Trump was referencing Clapper's testimony before Senate Judiciary subcommittee Monday that he was not aware of any evidence demonstrating collusion, but Clapper also said he had been unaware of an FBI investigation into the matter until FBI Director James Comey announced it publicly at a House hearing in March.
Minutes earlier, Trump issued his thinly veiled threat to Comey, an extraordinary development in the ongoing feud between the President and the agencies investigating alleged ties between his campaign and Russia.
The tweet seemed to suggest there are possibly recorded conversations between Trump and Comey that could be leaked to counter the former FBI director if necessary.
"James Comey better hope that there are no 'tapes' of our conversations before he starts leaking to the press," Trump tweeted.
Clapper also said he talked to Comey after Trump invited him to dinner shortly after he took office, saying Comey "was uneasy with it."
"I think anyone who is serving officer in the government, and you're asked by the President for dinner, I think it is professional courtesy," he said. "You're in a difficult position if you refuse to go, but I do know he was uneasy with it."
Comey was "taken aback" by Trump's request for a personal assurance or pledge of loyalty at the dinner, a source close to Comey told CNN
Clapper also contradicted the White House's account that the FBI rank and file had lost faith in Comey running the agency.
"From my vantage, the morale in the FBI was very high," he said. "And I can attest because of the high esteem and respect that people in the FBI had and still have for Jim Comey."