News of Gen Kim’s deployment to Russia came as the US said it believed around 8,000 North Korean troops had been sent to Kursk, which was invaded by Ukraine in August.

A career soldier, Gen Kim is also a member of the Workers’ Party of Korea Central Committee that rubber-stamps orders from Kim Jong-un.

Michael Madden, a non-resident fellow of the US-based Stimson Center analyst think tank, described Gen Kim as Kim Jong-un’s “top adviser on light infantry and the special operation forces”.

He also said it was telling that Gen Kim had attended seven of the dictator’s public engagements this year and two flood reconstruction projects.

“By publicising his presence at flood reconstruction work, to which he has no seeming connection, Pyongyang was telecasting that their special operations forces commander has direct, unfettered access to Kim Jong-un,” he said.

The Ukrainian statement to the UN described Gen Kim as the “commander-in-chief of North Korean forces in Russia”, which are estimated to be at least five infantry formations of 2,000–3,000 soldiers each.

But Mr Madden said that the North Korean leader may also have an alternative motive for sending Gen Kim to Russia.

He said that the North Korean dictator may have ordered him to supervise the hermit kingdom’s entire military deployment into the war rather than command troops on the ground.

“He is also probably coordinating with Russian counterparts and creating a reporting framework between deployed personnel and Pyongyang,” Mr Madden said.

News of Gen Kim’s deployment to Russia comes as Choe Son Hui, North Korea’s foreign minister, visits Moscow for talks with Sergei Lavrov, her Russian counterpart.

The Kremlin has not released any details of the talks but Russian news agencies have said that North Korea expects IT and other technical support from Russia in exchange for the thousands of artillery shells, missiles and now soldiers it has given to Russia over the past year.

This week, the Friedrich Naumann Foundation in Germany said that North Korea has supplied Russia with weapons worth an estimated £4.2billion.