"Russia is not helping us at all with North Korea," Trump said during an Oval Office interview with Reuters. "What China is helping us with, Russia is denting. In other words, Russia is making up for some of what China is doing."
China and Russia both signed onto the latest rounds of United Nations Security Council sanctions against North Korea imposed last year. There was no immediate comment from the Russian embassy in Washington on Trump's remarks.
With North Korea persisting as the major global challenge facing Trump this year, the president cast doubt during the 53-minute interview on whether talks with North Korean leader Kim Jong Un would be useful. In the past he has not ruled out direct talks with Kim.
"I'd sit down, but I'm not sure that sitting down will solve the problem," he said, noting that past negotiations with the North Koreans by his predecessors had failed to rein in North Korea's nuclear and missile programs.
"They've talked for 25 years and they've taken advantage of our presidents, of our previous presidents," he said.
He declined to comment when asked whether he had engaged in any communications at all with Kim, with whom he has exchanged public insults and threats, heightening tensions in the region.
Trump said he hoped the standoff with Pyongyang could be resolved "in a peaceful way, but it's very possible that it can't."
Trump praised China for its efforts to restrict oil and coal supplies to North Korea but said Beijing could do much more to help constrain Pyongyang.
The White House last week welcomed news that imports to China from North Korea, which counts on Beijing as its main economic partner, plunged in December to their lowest in dollar terms since at least the start of 2014.
'They Get Closer Every Day'
But Trump said Russia appears to be filling in the gaps left by the Chinese.
Western European security sources told Reuters in late December that Russian tankers had supplied fuel to North Korea on at least three occasions in recent months by transferring cargoes at sea in violation of international sanctions. Russia has denied breaching North Korea sanctions.
North Korea relies on imported fuel to keep its struggling economy functioning. It also requires oil for its intercontinental ballistic missile and nuclear programme.
"He can do a lot," Trump said of Russian President Vladimir Putin. "But unfortunately we don't have much of a relationship with Russia, and in some cases it's probable that what China takes back, Russia gives. So the net result is not as good as it could be."
Trump, who has grappled with nuclear tests and ballistic missile launches by North Korea since he took office a year ago, said Pyongyang is steadily advancing in its ability to deliver a missile to the United States.
"They're not there yet, but they're close. And they get closer every day," said Trump.
North Korea said after its last intercontinental ballistic missile launch in November that the test had put the U.S. mainland within range. Some experts agreed that based on the missile's trajectory and distance it had the capability to fly as far as Washington D.C.
They said, however, that North Korea had not yet offered any proof that it had mastered all technical hurdles, including development of a re-entry vehicle needed to deliver a heavy nuclear warhead reliably atop an ICBM, but it was likely that it soon would. Pyongyang could reach that milestone by the end of the year, some intelligence officials said.
Trump said he welcomed talks between North and South Korea over the Winter Olympics to be held in the South next month and said this could be an initial phase in helping defuse the crisis.
He would not say whether the United States has been considering a limited, pre-emptive attack to show the North that the United States means business.
"We're playing a very, very hard game of poker and you don't want to reveal your hand," he said.
U.S. officials had spoken of Trump's willingness to weigh a pre-emptive strike despite the risk of touching off a war. But in recent days Trump has appeared to signal more of an openness towards diplomacy.
(Reporting by Steve Holland, additional reporting by Jeff Mason, Roberta Rampton, Ayesha Rascoe, Jim Oliphant and Matt Spetalnick; Editing by Ross Colvin)
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)