WASHINGTON (Reuters) - Outgoing CIA Director John Brennan on Sunday issued a stern parting rebuke to Republican Donald Trump days before he assumes the U.S. presidency, advising him not to absolve Russia for its recent actions and warning him to watch what he says.

Brennan's comments, in an interview on "Fox News Sunday," laid bare the simmering tensions between the president-elect and the intelligence community he has criticized and is on the verge of commanding.

The CIA director said Trump needs to be mindful about his off-the-cuff remarks once he takes the oath of office on Friday, alluding to his penchant for making broad pronouncements on Twitter.

"Spontaneity is not something that protects national security