Director of National Intelligence Dan Coats on Monday directly challenged comments by President Trump, saying the U.S. intelligence community has been "clear in our assessments of Russian meddling in the 2016 election."

Coats has maintained an extremely low profile, rarely making public comments, since President Trump appointed him last year.

But last Friday, Coats spoke up. He said Russia remained the "most aggressive foreign actor" trying to disrupt the U.S. political system. "The warning signs are there. The system is blinking. And it is why I believe we are at a critical point," Coats said.

The remarks came the same day the Justice Department announced the indictment of 12 Russian military intelligence officials for hacking into Democratic Party emails in 2016.

Trump, standing alongside Russian President Vladimir Putin in Helsinki, acknowledged Monday that he had been briefed by Coats.

"My people came to me, Dan Coats came to me, some others, they said they think it's Russia," Trump said at the news conference. "I have President Putin. He just said it's not Russia. I will say this, I don't see any reason why it would be."

Shortly afterward, Coats issued a brief, blunt statement:

"We have been clear in our assessments of Russian meddling in the 2016 election and their ongoing, pervasive efforts to undermine our democracy, and we will continue to provide unvarnished and objective intelligence in support of our national security."

Coats was joined by many former intelligence officials who went much further in slamming Trump's performance in Helsinki.

Former CIA director John Brennan tweeted that Trump's remarks were "nothing short of treasonous."