NEW YORK (AP) — President-elect Donald Trump is continuing to lash out at critics in the intelligence community and Democrats in Congress who are vowing to skip his fast approaching inauguration ceremony.

The tough-talking Republican questioned whether the CIA director himself was "the leaker of fake news" in a Sunday night tweet.

The extraordinary criticism from the incoming president came hours after CIA chief John Brennan charged that Trump lacks a full understanding of the threat Moscow poses to the United States. He delivered a public lecture to the president-elect that further highlighted the bitter state of Trump's relations with American intelligence agencies.

Brennan said on "Fox News Sunday" that the president-elect's impulsivity could be dangerous.

Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.