The North Korean leader, Kim Jong-un, wants to visit Russia in late April for his first meeting with Vladimir Putin, Moscow has said.

"Following an invitation from Vladimir Putin … Kim Jong-un wants to visit Russia in the second half of April," the Kremlin said in a statement on his website on Thursday.

The announcement comes after North Korea said it had been tested with a "powerful warhead", as denuclearization talks with Washington appear to have stalled.

The Kremlin did not provide details of the exact date or location of the meeting, Russian and South Korean and Japanese media said it would be in Russia's far east.

Putin has long expressed his readiness to meet the North Korean leader.

Putin's press spokesman, Dmitry Peskov, said that Fiona Hill, an adviser to Donald Trump, had been in Moscow for talks with her Russian counterpart, Yuri Ushakov.

Trump's North Korea envoy, Stephen Biegun, which is in Moscow, the state department said.

A Pyongyang official, meanwhile, which is inspecting a train station in the city of Vladivostok, near Russia's border with North Korea, Russian state media reported.

Russia has relatively warm ties with the reclusive regime and provides some food aid.

Kim Jong-il, Traveling to Siberia to meet Dmitry Medvedev, Russia's then president.

Kim Jong-il, who died shortly after the visit, told Medvedev his state was prepared for renounce nuclear testing.