President Donald Trump on Friday welcomed Russian and Chinese help with North Korean nuclear negotiations, despite Kim Jong Un accusing the US of "bad faith" at a first summit with Vladimir Putin.
"I appreciate that Russia and China are helping us," he told reporters at the White House.
Putin's first summit with Kim on Thursday was seen as a response to the failure of a Kim-Trump meeting in Hanoi in February, where talks broke down without agreement.
But Trump indicated that he does not see China and Russia as rivals in the struggle to get North Korea to give up its nuclear arsenal.
"China is helping us because I think they want to. They don't need nuclear weapons right next to their country," Trump said.
"I think we're doing very well with North Korea. A lot of progress is being made," he added.
"I appreciated President Putin's statement yesterday. He wants to see it done also. I think there is a lot of excitement for getting a deal done with North Korea."
Kim left his summit with Putin indicating that he has cooled on the much-touted bid by Trump to woo his country into a non-nuclear future.
The official Korean Central News Agency reported that Kim told Putin the US had adopted a "unilateral attitude in bad faith" at the Hanoi summit.
"Peace and security on the Korean peninsula will entirely depend on the US future attitude, and the DPRK will gird itself for every possible situation," Kim was quoted as saying.
Putin backed the North's demand for "security guarantees" in its standoff with the United States over the nuclear capability, which Washington wants to see scrapped entirely, but Pyongyang fears would leave the country vulnerable.
Trump has claimed that he and Kim have a special friendship and even "love."
But their second summit, held in Hanoi, broke down in late February without a deal, after cash-strapped Pyongyang demanded immediate relief from sanctions.
Russia has also called for the sanctions to be eased, while the US has accused Moscow of trying to help Pyongyang evade some of the measures.
In another setback just a week ago, Pyongyang demanded the removal of US Secretary of State Mike Pompeo from the stalled nuclear talks.
On Thursday, Putin emerged from the meeting saying that like Washington, Moscow supported efforts to reduce tensions and prevent nuclear conflicts.
But he also insisted that the North needed "guarantees of its security, the preservation of its sovereignty".
It was "what the North has been saying all along" said Kim Keun-sik, professor of North Korean Studies at Kyungnam University, adding that Putin's support for Pyongyang's stance was the "biggest prize" Kim won in Vladivostok.
Putin flew on to another summit in Beijing the same day, while Kim stayed in Vladivostok and had been due to take part in a series of cultural events.
The mercurial North Korean kept officials in suspense about his post-summit plans.
A wreath-laying ceremony was delayed by two hours on Friday morning, with an honour guard kept waiting and the red carpet rolled up.
Kim eventually showed up and the wreath was laid. Solemn music played as he stood, hat in hand wearing a black double-breasted waistcoat.
Russian media had reported that Kim would be visiting the city's aquarium and seeing a ballet, but the visit was apparently cut short.
Kim instead turned up at the train station in the afternoon and, after a final departure ceremony with a military band, boarded his train and left around 3:30 pm (0530 GMT).
Putin and Kim said they were looking to strengthen ties that date back to the Soviet Union's support for the founder of North Korea, Kim's grandfather Kim Il Sung.
Kim said he hoped to usher in a "new heyday" in ties.
The North Korean strongman invited Putin to visit "at a convenient time" and the invitation was "readily accepted", KCNA said.
"Kim met Putin because he wanted to show he had someone on his side," said Lee Woo-young, a professor at the University of North Korean Studies in Seoul.
"Kim is seeking the upper hand for future talks with the US and meeting foreign leaders like Putin can help him do that."
But Washington was unlikely to be swayed, he added, with analyst Kim also doubting the US would be "surprised or alarmed".