(CNN) — Former CIA Director John Brennan called President Donald Trump’s performance at Monday’s news conference with Russian President Vladimir Putin “nothing short of treasonous.”

At the news conference following his one-on-one meeting Putin in Helsinki, Finland, Trump declined to endorse the US intelligence community’s assessment that Russia interfered in the 2016 election over Putin’s denial, saying the Russian President was “extremely strong and powerful” in his denial.

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“Donald Trump’s press conference performance in Helsinki rises to & exceeds the threshold of ‘high crimes & misdemeanors.’ It was nothing short of treasonous,” Brennan, a frequent critic of Trump, tweeted during the event. “Not only were Trump’s comments imbecilic, he is wholly in the pocket of Putin. Republican Patriots: Where are you???”

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Brennan served as director of the CIA from 2013 through January 2017.

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