WASHINGTON (NYTIMES) - President Donald Trump, in the words of a former CIA director, Michael Hayden, appeared "raw, naked and unfiltered."

John Brennan, another former spy chief, called the president's performance "treasonous." And Mark Lowenthal, a former CIA assistant director and congressional intelligence official, said it was "just beyond the pale."

Trump has frequently questioned the conclusions of his own spies that Russia attempted to influence the 2016 presidential election and has tried to do the same regarding potential Russian meddling in this year's midterms. But this time he did it standing next to President Vladimir Putin of Russia, who has repeatedly denied that Russia made any effort to interfere in the vote - a denial that US intelligence officials say is a nothing more than a hollow lie.

But not Trump. Asked Monday at his news conference in Helsinki whether he believed his own people or Putin, the US president appeared to come down on the side of the Russian leader. Putin was "extremely strong and powerful in his denial today," Trump said.

Then Trump seemed to throw his support behind a proposal from Putin for some kind of joint investigation into the 12 Russian intelligence officers indicted last week by Robert Mueller, the special counsel, for their alleged role in hacking into Democratic Party servers and state election systems in 2016.

"What he did is an incredible offer," Trump said of his Russian counterpart. "He offered to have the people working on the case come and work with their investigators with respect to the 12 people. I think that's an incredible offer. OK?"

Trump later appeared to try to walk back his comments in a tweet.

"As I said today and many times before, 'I have GREAT confidence in MY intelligence people,'" Trump wrote. "However, I also recognise that in order to build a brighter future, we cannot exclusively focus on the past - as the world's two largest nuclear powers, we must get along!"

But the tweet did little to mollify US intelligence officials past and present, especially related to Putin's offer to aid the Mueller investigation.

"The odds of that happening are a negative number," said Hayden, who ran the CIA and National Security Agency under President George W. Bush.

He expected the idea to go the way of the "impenetrable Cyber Security unit" Trump said he discussed when he met with Putin last July.

"It's not going to happen," he said, noting that even with the British and Australians - arguably the United States' two closest allies - "we're a little private with our stuff."

The reason, current and former intelligence officials said, was simple: Inviting in the Russians would result in sharing what is known in the intelligence world as sources and methods. Far more than the information spies collect, it is the sources of that information and the methods through which it is gathered that intelligence agencies consider their most closely guarded secrets.

Intelligence officials even hesitate when sharing such information with members of congressional oversight committees.

Giving Russian intelligence operatives a chance to figure who inside their government is aiding American spies, or how the United States was listening in on conversations between Russian officials was unimaginable, they said.

Hayden said the president's "departure point for speech and thought is not objective reality." "He was probably thinking that he was getting out of a very uncomfortable question," Hayden added.

Trump did not get out of answering a question. If anything, he deepened the mistrust many inside US spies agencies have of their president.

The remarks prompted a rare public response from Trump's own director of national intelligence, Daniel R. Coats, who said in a statement, "We have been clear in our assessments of Russian meddling in the 2016 election and their ongoing, pervasive efforts to undermine our democracy."

Two US officials said the White House did not approve his statement.

Few other currently serving intelligence officials were willing to speak publicly about Trump's remarks - intelligence officials are, after all, expected to work for any president no matter their politics and, in any case, most work in offices where they cannot easily speak with reporters or any outsiders. Those that would talk spoke only on the condition of anonymity for fear of jeopardising their careers.

But all were unanimous in saying that they and their colleagues were aghast at how Trump had handled himself with Putin.

One official summed up what appeared to be the consensus view, saying that it was clear whose side Trump was on, and "it isn't ours."

Brennan, the former CIA director, was far more blunt in an assessment delivered via the president's favorite medium, Twitter.

"Donald Trump's press conference performance in Helsinki rises to & exceeds the threshold of 'high crimes & misdemeanors,'" Brennan wrote. "It was nothing short of treasonous. Not only were Trump's comments imbecilic, he is wholly in the pocket of Putin. Republican Patriots: Where are you???"

Lowenthal, who served as an intelligence official in Congress and at the White House under Republicans, said that he had never seen a president so openly break with his own spy agencies. He rattled off a list of times that presidents publicly broke with their intelligence chiefs: President Kennedy fired his CIA director after the Bay of Pigs disaster. President Richard Nixon dismissed the agency's chief for refusing to help cover-up the Watergate break in. And President Bill Clinton's director quit, complaining that he had no real access to the Oval Office.

But Trump's performance Monday was "just beyond the pale," Lowenthal said.

"He's the best president that Russia's ever had," Lowenthal added.