Russian soldiers have been filmed giving North Korean troops battlefield training and language lessons, with some of Kim Jong-un’s men picking up swear words.

In one video, a small group of Pyongyang’s soldiers preparing to head to the front line is shown how to lay landmines by Moscow’s military instructors.

The training is interrupted when the North Koreans, who are wearing Russian uniforms, appear not to understand what they are supposed to do.

One fresh-faced soldier points at a word from a sheet and asks his Russian trainer how to pronounce it, in footage dated Nov 5.

“Sla-slavo?” he asks, attempting to say the Russian word for “weakly” or “gently”.

“Slabo,” the Russian replies. “[With a] B.”

Trying to make friends

In a video from October, a Russian soldier is filmed attempting to make friends with a North Korean, who rudely brushes him off.

The fighter, who says he is from the Russian-occupied Georgian territory of Abkhazia, asks: “You, me, Abkhazia, Korea, friends?”

“I don’t give a f—,” the North Korean responds, as laughter is heard off camera.

Last month, a South Korean intelligence official revealed that Russia was teaching North Korean soldiers around 100 basic military terms, such as “back to your position”, “fire” and “launch”.

In an intercepted phone call released by Ukrainian intelligence in October, Russians soldiers expressed doubts that there would be enough interpreters for the foreign troops under their command.

A Russian officer was heard promising that one interpreter would be assigned to every group of 30 North Korean soldiers, a claim of which other Russians on the call sounded sceptical.

On Tuesday, the US confirmed that North Korean troops had begun combat operations against Ukrainian forces.

Vedant Patel, a state department spokesman, said: “Over 10,000 DPRK [North Korean] soldiers have been sent to eastern Russia, and most of them have moved to the far western Kursk Oblast, where they have begun engaging in combat operations with Russian forces.”