Outgoing CIA Director John Brennan issued a stern parting rebuke to Republican Donald Trump days before he assumes the US presidency, advising him not to absolve Russia for its recent actions and warning him to watch what he says.
Mr 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 criticised and is on the verge of commanding.
The CIA director said Mr 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 interests and so therefore when he speaks or when he reacts, just make sure he understands that the implications and impact on the United States could be profound," Mr Brennan said.
"It's more than just about Mr Trump. It's about the United States of America."
Mr Trump last week accused the intelligence community of leaking information about an unsubstantiated report on compromising information the Russians have accumulated against Mr Trump. On Twitter, he accused intelligence agencies of practices reminiscent of Nazi Germany.
"What I do find outrageous is equating intelligence community with Nazi Germany," Mr Brennan said. "I do take great umbrage at that."
Mr Brennan also questioned the message it sends to the world if the president-elect broadcasts he does not have confidence in the United States' own intelligence agencies.
For months, Mr Trump had publicly doubted US intelligence conclusions that Russia was behind cyber attacks against Democratic political groups before admitting in a news conference on Wednesday that he thinks Russia was behind the hacking.
The US intelligence community concluded in a report presented to US President Barack Obama and Mr Trump last week that Russia tried to sway the outcome of the 8 November election by hacking and other means. It did not make an assessment on whether they were successful.
Trump team rebukes civil rights leader
Meanwhile Mr Trump's vice president and top aides joined the US President-elect in criticising a historic civil rights activist and lawmaker for questioning the legitimacy of his election win.
US Representative John Lewis, a Georgia Democrat, told NBC's Meet the Press he thought hacking by Russians had helped Mr Trump, a Republican, get elected in November.
Mr Lewis said he does not plan to attend Mr Trump's swearing in on Friday, the first time he would miss such an event since being elected to the House in 1986.
Vice President-elect Mike Pence, incoming White House Chief of Staff Reince Priebus and Mr Trump's spokesman Sean Spicer characterised Mr Lewis' remarks as disappointing and damaging to the reputation of US democracy.
"For someone of his stature not just in the civil rights movement but in voting rights to make a comment that he did not consider Donald Trump to be a legitimate president I think is deeply disappointing. I hope he reconsiders both statements," said Mr Pence.
Mr Lewis, 76, who has been a civil rights leader for more than half a century, was beaten by police during a march he helped lead in 1965 in Selma, Alabama, drawing attention to hurdles preventing blacks from voting.
He protested alongside leader Martin Luther King Jr that day and on other occasions. The spat comes ahead of tomorrow’s federal holiday that honours Mr King.
Speaking on ABC's This Week, Mr Priebus said Mr Lewis' comments, given his position in society, were irresponsible.
"We need folks like John Lewis, and others who I think have been champions of voter rights, to actually recognise the fact that Donald Trump was duly elected," said Mr Priebus. "I think putting the United States down across the world is not something that a responsible person does."
"It was John Lewis that attacked Donald Trump. Donald Trump has a right to respond to that, and he did. And forcefully," Mr Spicer said on Fox News.