North Korean leader Kim Jong Un may travel to Russia soon to meet President Vladimir Putin as the Kremlin tries to acquire military equipment for use in its war in Ukraine, a US official has said.

The official said the US expects Mr Kim to make the trip within the month.

The official said the US is not sure exactly where or when the meeting would take place, but the Pacific port city of Vladivostok would be a likely possibility given its relative proximity to North Korea.

National Security Council spokeswoman Adrienne Watson noted on Monday that Russian defence minister Sergei Shoigu travelled to Pyongyang last month and tried to persuade North Korea to sell artillery ammunition to Russia.

Ms Watson said: “We have information that Kim Jong Un expects these discussions to continue, to include leader-level diplomatic engagement in Russia.”

She added that the US is urging North Korea “to cease its arms negotiations with Russia and abide by the public commitments that Pyongyang has made to not provide or sell arms to Russia”.

Mr Shoigu said on Monday that the two countries may hold joint war games.

The New York Times first reported that Mr Kim planned to meet Mr Putin in Russia this month.

The White House said last week that it had intelligence indicating that Mr Putin and Mr Kim swapped letters following Mr Shoigu’s visit.

National Security Council spokesman John Kirby said the letters were “more at the surface level” but that Russian and North Korean talks on a weapons sale were advancing.