DANANG, Vietnam — President Trump said Saturday that he believed President Vladimir Putin is sincere in his denials of interference in the 2016 election, calling questions about Moscow’s meddling a politically motivated “hit job’’ that is hindering cooperation with Russia on life-or-death issues.

Speaking after meeting privately with Putin at the Asia Pacific Economic Cooperation summit in Danang, Trump said that he had again asked whether Russia had meddled in the contest but that the continued focus on the issue was insulting to Putin.

“He said he didn’t meddle — I asked him again,’’ Trump told reporters traveling with him aboard Air Force One as he flew to Hanoi for more meetings. “You can only ask so many times. I just asked him again. He said he absolutely did not meddle in our election.’’

Trump did not answer a direct question about whether he believed Putin’s denials, but his account of the conversation indicated he was far more inclined to accept the Russian president’s assertions than those of his own intelligence agencies, which have concluded that Putin directed an elaborate effort to interfere in the vote.

“Every time he sees me he says, ‘I didn’t do that,’ and I really believe that when he tells me that, he means it,’’ Trump said of Putin. “I think he is very insulted by it, which is not a good thing for our country.’’

Trump said it was time to move past the issue so that the United States and Russia could cooperate on confronting the nuclear threat from North Korea, solving the Syrian civil war, and working together on Ukraine.

His remarks inspired immediate ridicule from Democratic lawmakers, including Representative Adam B. Schiff of California, the top Democrat on the House Intelligence Committee.

“You know who else is insulted by it, Mr. President? The American people,’’ Schiff said on Twitter. “You believe a foreign adversary over your own intelligence agencies.’’

Trump heaped disdain on the former leaders of three US intelligence agencies — John O. Brennan, the former CIA director; James R. Clapper Jr., the former director of national intelligence; and James Comey, the FBI director he fired this year — appearing to suggest that they were less trustworthy than Putin.

“I mean, give me a break — they’re political hacks,’’ Trump said. “You have Brennan, you have Clapper, and you have Comey. Comey’s proven now to be a liar, and he’s proven to be a leaker, so you look at that. And you have President Putin very strongly, vehemently says he had nothing to do with that.’’

After Trump’s comments, General Michael V. Hayden, a former director of both the CIA and the National Security Agency, wrote on Twitter that the CIA had told him that the agency’s director “stands by and has always stood by’’ its January findings regarding Russian interference.

“The intelligence assessment with regard to Russian election meddling has not changed,’’ he wrote.

The president said lingering questions about whether his campaign aides had worked with Russia to sway the election were souring Washington’s relationship with Moscow on a host of vital security issues.

“Having a good relationship with Russia is a great, great thing,’’ Trump said. “This artificial Democratic hit job gets in the way, and that’s a shame, because people will die.’’

The allegations of collusion are the subject of an investigation by special counsel Robert Mueller, as well as multiple congressional inquiries.

Trump’s comments about the Russian president and his warning about deteriorating Moscow ties came after the close of the APEC conference in Danang, where the White House steered clear of a formal meeting between the two men and made a point of announcing Friday that one would not occur.

The small group of reporters who travel with Trump were barred from covering his activities for most of Saturday, leaving them in the dark about his informal interactions. But video showed him shaking hands with Putin on Friday evening at a gala dinner and chatting with him Saturday before and after a group photograph of the APEC leaders.

The Kremlin released a statement saying that the leaders had met and struck an agreement on Syria, but the White House did not confirm the information for most of the day. Then, in a question-and-answer session with reporters later, Trump said he had had two or three brief conversations with Putin, mostly about Syria.

The talks were described in a joint statement by United States and Russia that reaffirmed previous commitments to defeat the Islamic State and to untangle conflicts between their forces on the Syrian battlefield.

It said that Trump believed he had had “a good meeting’’ with Putin on common efforts that, once in place, would “save thousands of lives.’’

Trump’s description of the exchange about election meddling was striking because it suggested that he concurred with Putin’s oft-stated contention that the issue was a contrived story that had been allowed to become an irritant between the United States and Russia, to the detriment of both countries.

Putin similarly brushed off recent revelations that Russians had contacts with Trump’s campaign team as a “domestic political struggle’’ in the United States.