A former spokesman for Hillary Clinton Hillary Diane Rodham ClintonJeff Flake: Republicans 'should hold the same position' on SCOTUS vacancy as 2016 Momentum growing among Republicans for Supreme Court vote before Election Day Warning signs flash for Lindsey Graham in South Carolina MORE on Tuesday said it's "impossible to believe" President Trump Donald John TrumpUS reimposes UN sanctions on Iran amid increasing tensions Jeff Flake: Republicans 'should hold the same position' on SCOTUS vacancy as 2016 Trump supporters chant 'Fill that seat' at North Carolina rally MORE did not know anything about Russian efforts to meddle in the 2016 presidential race.

"It's impossible to believe that the president himself did not know about this," Brian Fallon said in an interview on CNN about a meeting Donald Trump Jr. had with a Russian lawyer who promised to offer compromising information about Clinton, the Democratic presidential nominee.

Fallon's comments came after Trump Jr. released a chain of emails detailing his conversations about setting up the meeting.

ADVERTISEMENT

Fallon said he never expected to see evidence that would be "as much of a smoking gun as this email."

"I thought that at best, at the end of this investigation, you'd have a bunch of circumstantial evidence that would be a close call in terms of — having any criminal repercussions to it," Fallon continued.

"But this is as clear as day."

Trump Jr. released the emails after The New York Times reported that he had met with the Russian lawyer and was told before the meeting that the information was part of a Russian government effort to help his father's presidential campaign.

Fallon said Tuesday he thinks it is "impossible to believe that the president himself was unaware of this apparent effort by the Russian government that was known to others in the Trump campaign."

Fallon also said he expects Trump Jr. will now have to answer questions under oath and will be asked about conversations he may have had with his father in the months after the meeting with the Russian lawyer.

"Even if the president didn't know about this meeting itself," Fallon said, "it's impossible to think that for all the months during the campaign, as the emails were being leaked out by the Russians, that there wasn't at some point a conversation where the son revealed to the father that he knew of a Russian government plot to help the Trump campaign."