The two leaders' first one-on-one did not indicate major changes in North Korea's position: Putin said Kim is willing to give up nuclear weapons, but only if he gets ironclad security guarantees.

However, Putin said Kim urged him to explain the nuances of North Korea's position to President Donald Trump.

Such an interlocutor role could be meaningful in light of Trump's apparent admiration of the Russian leader.

Trump has said he "fell in love" with Kim, possibly indicating a proclivity to being swayed toward accommodation with the North Korean leader, although that declaration came before the Trump-Kim summit in Hanoi in February that collapsed in disagreement.

After Thursday's summit in the Pacific port city of Vladivostok, about 120 kilometres from the North Korean border, Putin stressed that Moscow and Washington both want North Korea to abandon its nuclear weapons.

But, he said, the security guarantees Kim demands in exchange should be underwritten by multiple countries, hinting at an arrangement like the six-nation talks Russia participated in until their collapse in 2009.

Putin later headed for a two-day trip to Beijing, where he said he will inform the Chinese leadership about the summit.

"And we will just as openly discuss this issue with the US leadership," Putin said. "There are no secrets. Russia's position always has been transparent. There are no plots of any kind."

Putin's remarks reflect Kim's growing frustration with Washington's efforts to maintain "maximum pressure" until the North commits to denuclearisation.

But his characterisation of Kim's comments also suggests there have been no major changes in North Korea's basic position.

North Korea has all along contended that it needs its nuclear arsenal to defend itself against what it sees as US hostility and wants concrete reassurances of its safety, including the removal of the American nuclear threat as an integral part of the denuclearisation of the entire Korean Peninsula.

Australian Associated Press