President Vladimir Putin feels insulted by allegations of Russian interference in the 2016 US election, Donald Trump has said after meeting him briefly at an Asia-Pacific summit in Vietnam.
"He said he absolutely did not meddle in our election," the US leader said.
Mr Trump, who defeated Democratic rival Hillary Clinton, said the allegations were a "Democratic hit job".
The US intelligence community concluded earlier that Russia had indeed tried to sway the poll in favour of Mr Trump.
The US justice department has appointed special investigator Robert Mueller to examine any possible collusion involving Mr Trump's team, and legal action has already been taken against several former aides.
The contents of the emails, passed to Wikileaks and posted online, were embarrassing to the Democrats and shook up the presidential campaign, which ended in defeat for Hillary Clinton.
In addition to the Mueller inquiry, congressional committees have been set up to carry out their own investigations.
Relations between the US and Russia have been strained for years, with the Kremlin long accusing Washington of seeking to sway elections in Russia and other ex-Soviet states including Ukraine and Georgia.
While Russian hackers are widely suspected of involvement, there has been no conclusive link to the Kremlin.
Denying that Russia had tried to interfere last year by fostering contacts with Mr Trump's campaign, Mr Putin told reporters in Vietnam: "Everything about the so-called Russian dossier in the US is a manifestation of a continuing domestic political struggle."
What does Mr Trump say to the allegations?
He said he believed Mr Putin had been "very insulted by" the allegations and that was "not a good thing" for America.
"He [Putin] said he didn't meddle," he added. "I asked him again."
Asked if he believed Mr Putin, he replied, "He is very, very strong in the fact that he didn't do it. You have President Putin very strongly, vehemently says he has nothing to do with that. Now, you are not going to get into an argument, you are going to start talking about Syria and the Ukraine."
Donald Trump once again goes against the findings of his own intelligence agencies.
Because although the US justice department is investigating the scale and nature of Russian interference in the election of 2016 (and any links to the Trump campaign), the American intelligence community has already long determined that Russia did, indeed, interfere.
Yet Mr Trump suggested this story was not only entirely fabricated by his political opponents, it might even be costing lives in Syria, because it is getting in the way of his relationship with the Russian president and hampering their ability to help solve the conflict together.
"People will die because of it, and it's a pure hit job, and it's artificially induced and that's a shame," he said.
It is hard to know what the president hopes to achieve with this type of rhetoric. The investigation goes on.