By Veronica Stracqualursi, CNN

(CNN) -- Former Director of National Intelligence James Clapper confirmed Thursday that Donald Trump was briefed on US intelligence findings that Russian President Vladimir Putin personally ordered cyberattacks to attempt to sway the 2016 presidential election.

Clapper told CNN's "New Day" that he and other intelligence officers briefed Trump, who was President-elect at the time, and his team on January 6, 2017. CNN has previously reported that Trump was briefed on the report by the US intelligence community, which found that Putin ordered an "influence campaign" aimed at helping Trump and hurting Hillary Clinton in the 2016 presidential election.

In the "New Day" interview Thursday, Clapper said Trump listened to the briefing with "some skepticism."

"What struck me and others as quite unusual was before we left the room, they started writing a press release about our encounter and were trying to say that the Russian meddling -- the Russian interference had no impact on the election," Clapper said Thursday. "We didn't say that. We could not say that, that isn't the charter or capability of the intelligence community to do that. But I do think there was skepticism from the get-go -- from that day to this day -- that indicated that anything that attacked the legitimacy or questioned the legitimacy of now-President Trump's election, he just couldn't get his head around. He exhibited that that day and he has ever since."

Clapper has frequently criticized Trump's behavior toward Russia, including in his news conference Monday with Putin in Helsinki, Finland.

Standing beside Putin, Trump did little to counter the Russian leader's denials and show support for the US intelligence community's findings that Russia meddled in the election.

"I've been trying my best to give the President the benefit of the doubt and always expressed potential other theories as to why he behaves as he does with respect to Russia generally and Putin specifically," Clapper told CNN Thursday.

"But more and more I come to a conclusion after the Helsinki performance and since, that I really do wonder if the Russians have something on him."

At the Helsinki news conference, Putin was asked about whether the Russian government had any compromising evidence on Trump or his family. He did not directly deny that his government had any and said he was not aware that Trump was in Moscow in 2013 for a Miss Universe pageant, a dubious claim given that Trump tweeted that he hoped the Russian leader would attend and at least one member of Trump's entourage was in touch with Kremlin officials about Putin attending the event, according to congressional testimony.

Trump also has dismissed a dossier of opposition research that suggested Russians may have compromising information on him as "fake." Some of the dossier, however, has been corroborated by investigators.

On Wednesday, Trump criticized Clapper, who was appointed as DNI chief by President Barack Obama, as someone in whom he has "no confidence" during an interview with CBS News.

Clapper hit back Thursday: "I think the feeling is mutual."