WATCH

Trump Attacks CIA Director: 'Was This the Leaker of Fake News?'

The Sunday night jab was a reference to a recent intelligence briefing that raised questions about Trump's connections to Russian President Vladimir Putin.

U.S.President-elect Donald Trump gestures to people in the lobby after speaking to the news media with television personality Steve Harvey and businessman Greg Calhoun after their meeting at Trump Tower in New York, U.S., January 13, 2017.
Reuters

Donald Trump is lashing out at CIA chief John Brennan for saying the president-elect doesn't understand the threat posed by Russia.

Trump tweeted of Brennan, "Was this the leaker of Fake News?"

The Sunday night jab was a reference to a recent intelligence briefing that raised questions about Trump's connections to Russian President Vladimir Putin.

The CIA director said Sunday morning on Fox News that Trump lacks "full appreciation and understanding" of the implications of lifting sanctions on Russia.

Trump acknowledged Brennan's criticism and said he "couldn't do much worse" as president.  Trump's choice to lead the agency is former Rep. Mike Pompeo.