Are North Korean troops joining Russia’s war in Ukraine?

Russia’s army is forming a unit of some 3,000 North Koreans, a Ukrainian military intelligence source has told the BBC, in the latest report suggesting that Pyongyang is forming a close military alliance with the Kremlin.

So far the BBC has yet to see any sign of such a large unit being formed in Russia’s Far East, and Kremlin spokesman Dmitry Peskov has dismissed reports of North Korean involvement.

“This is not only British intelligence, it is also American intelligence. They report it all the time, they don’t provide any evidence,” he said.

There is no doubt Moscow and Pyongyang have deepened their levels of cooperation in recent months. North Korean leader Kim Jong Un sent Vladimir Putin a birthday message only last week calling him his “closest comrade”.

Ukraine’s Volodymyr Zelensky has spoken of North Korea joining the war, and South Korea’s defence minister said this month that the chance of a North Korean deployment in Ukraine was “highly likely”.

The biggest question mark is over the numbers involved.

A military source in Russia’s Far East confirmed to BBC Russian that “a number of North Koreans have arrived” and were stationed in one of the military bases near Ussuriysk, to the north of Vladivostok. But the source refused to give a precise number, other than that they were “absolutely nowhere near 3,000”.

Military experts have told us they doubt Russian army units can successfully incorporate North Korean soldiers in their thousands.

“It wasn’t even that easy to include hundreds of Russian prisoners at first – and all those guys spoke Russian,” one analyst – who is in Russia so didn’t want to be named – told the BBC.

Even if they did number 3,000, it would not be big in a battlefield sense, but the US is as concerned as Ukraine.

“It would mark a significant increase in their relationship,” said US state department spokesman Matthew Miller, who saw it as “a new level of desperation by Russia” amid battlefield losses.