DA NANG, Vietnam — With new details emerging about contacts between Russian officials and advisers to President Donald Trump’s 2016 presidential campaign, Trump again declined to press concerns about Russian interference in the election last year with Russian President Vladimir Putin while the two leaders met Saturday in Vietnam.

“Every time he sees me, he says, ‘I didn’t do that,’ ” Trump said aboard Air Force One while traveling between Da Nang and Hanoi during his 12-day Asian trip. “And I believe, I really believe that when he tells me that. He means it.”

Trump instead lashed out at former U.S. national security officials who sounded the alarm about Russian interference, including former CIA Director John Brennan, former Director of National Intelligence James Clapper and former FBI Director James Comey, whom Trump fired this year.

“They’re political hacks,” Trump said. “Comey is 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.”

Trump’s comments came after days of equivocation from the White House over whether Trump would meet with Putin. Both men were in Da Nang to attend the Asia-Pacific Economic Cooperation summit. Trump said he had “two or three very short conversations” with Putin during the past two days to discuss Syria. They issued a joint statement Saturday promising further cooperation in seeking a political solution to the country’s civil war.

U.S. intelligence agencies already have concluded Russia engaged in a campaign to influence the election, hacking into Democratic emails that later were leaked and using a variety of online tools to spread fake news and other propaganda.

Now, the investigation into potential collusion between the Russian government and Trump’s campaign is reaching a new stage.

Trump’s campaign chairman, Paul Manafort, was charged last month with money laundering and conspiracy, and a second former aide, Richard W. Gates III, also was charged in the indictment, though none of those charges were related to allegations of Russian election meddling.

The same day, it was announced that George Papadopoulos, a foreign policy adviser for the campaign who worked to set up contacts with Russian officials, pleaded guilty to lying to the FBI and has been cooperating with investigators.

During the Asia trip, White House staff members have seemed intent on downplaying Trump’s interactions with Putin. Press secretary Sarah Huckabee Sanders said Friday the two would not have a formal meeting, despite reports in Russia that they would, because there was not time in the schedule. She allowed, however, that they were bound to run into each other and likely would talk.

In Vietnam, Trump said Putin told him he “absolutely did not meddle in our election.”

“Look, I can’t stand there and argue with him. I’d rather have him get out of Syria” and “work with him on the Ukraine,” Trump said.

“That whole thing was set up by the Democrats,” Trump said, though it was unclear whether he was blaming Democrats for Russia’s election interference or for the investigation into his campaign’s possible collusion with the Russians.

Trump also raised the meddling issue with Putin in July, during the Group of 20 summit in Hamburg, Germany, yielding similar results. Putin came away from the meeting saying Trump was “satisfied” with his denials. Secretary of State Rex Tillerson told a different version, saying the two countries might have “an intractable disagreement” over the issue.

Trump said Saturday he and Putin “have a good feeling toward getting things done” and that a stronger relationship with Russia “would be a great thing, not a bad thing.”

He said China has been more helpful than Russia in efforts to contain North Korea’s nuclear program. He said Putin is insulted by accusations of meddling and blamed “the lack of a relationship that we have with Russia because of this artificial thing that’s happening with this Democratic-inspired thing.” At another point, he called the Russian collusion investigation an “artificial Democratic hit job.”

Responding to criticism he had not raised human rights issues on his trip through Asia as strongly as his predecessors, Trump also asserted he had, “but I also raise issues on many other things.”

And he said while meeting with Chinese President Xi Jinping this week, he “very briefly” raised the issue of opening China to Twitter and other social media platforms now censored in the country. But the president said he was more focused on trade and North Korea.

Trump declined to say whether Republican Alabama Senate candidate Roy Moore should drop out of the race following reports he molested a 14-year-old girl nearly four decades ago. Sanders issued a statement Friday on Trump’s behalf calling it a “mere allegation” while adding “if these allegations are true, Judge Moore will do the right thing and step aside.”

Trump said he was too busy on his Asia trip to devote much time to the issue.

“I’m dealing with the president of China, the president of Russia,” he said. “I’m dealing with the folks over here.”