The Russian army is a unit of around 3,000 North Koreans, a Ukrainian military intelligence source told the BBC. The latest report suggests that Pyongyang is forming a close military alliance with the Kremlin.

So far the BBC has seen no sign of such a large unit forming in the Russian Far East, and Kremlin spokesman Dmitry Peskov has dismissed reports of North Korean involvement.

“These are not just British intelligence services, they are also American intelligence services. They report on it all the time, they don’t provide any evidence,” he said.

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

Ukraine’s Volodymyr Zelensky has spoken of North Korea’s participation in the war, and South Korea’s defense minister said this month that the likelihood of a North Korean deployment to Ukraine was “very likely.”

The biggest question mark concerns 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 at one of the military bases near Ussuriysk, north of Vladivostok. But the source declined to give an exact number, other than to say it was “definitely not close to 3,000.”

Military experts have told us they doubt Russian military units can successfully absorb thousands of North Korean soldiers.

“In the beginning it wasn’t even that easy to involve hundreds of Russian prisoners – and all those guys spoke Russian,” one analyst – who is in Russia and therefore asked not to be named – told the BBC.

Even if there were 3,000, that wouldn’t be large in terms of the battlefield, but the US is as concerned as Ukraine.

“It would be a significant improvement in their relationship,” said U.S. State Department spokesman Matthew Miller, who saw it as “a new level of desperation from Russia” amid its battlefield losses.

In June, Vladimir Putin toasted a “peaceful and defensive” pact with Kim Jong Un.

And there is growing evidence that North Korea is supplying Russia with munitions, as recently demonstrated by the recovery of a missile in Ukraine’s Poltava region.

In fact, reports of mines and grenades supplied by Pyongyang date back to December 2023 in Telegram chats involving Russia’s military communities.

Russian soldiers stationed in Ukraine have often complained about the quality of ammunition and that dozens of soldiers have been injured.

Kiev suspects that a unit of North Korean soldiers is preparing in the Ulan-Ude region, close to the Mongolian border, before deploying to Russia’s Kursk province, where Ukrainian forces launched an incursion in August.

“They could monitor some parts of the Russian-Ukrainian border, which would free up Russian units to fight elsewhere,” said Valeriy Ryabykh, editor of the Ukrainian publication Defense Express.

“I rule out the possibility of these units immediately appearing on the front line.”

Ryabach is not alone in this thought.

North Korea may have some 1.28 million active soldiers, but its military, unlike the Russian military, has no recent experience in combat operations.

Pyongyang has emulated the old Soviet model in its armed forces, but it is unclear how its main force, made up of motorized infantry units, might fit into the war in Ukraine.

Then there is the obvious language barrier and unfamiliarity with Russian systems that would complicate any combat role.

That doesn’t rule out the North Korean military’s participation in Russia’s full-scale war in Ukraine, but experts are most recognized for their technical and construction capabilities, not for their fighting.

What they both have are shared incentives.

Pyongyang needs money and technology, Moscow needs soldiers and ammunition.

“Pyongyang would be well paid and perhaps gain access to Russian military technology that Moscow would otherwise have been reluctant to transfer to North Korea,” said Andrei Lankov, director of the Korea Risk Group.

“It would also give their soldiers real combat experience, but there is also the risk of exposing North Koreans to life in the West, which is a significantly more prosperous area.”

For Putin, there is an urgent need to make up for the significant losses during more than two and a half years of war.

Valeriy Akimenko of the British Conflict Studies Research Center believes that deploying North Koreans would help the Russian leader deal with the fact that the previous round of mandatory mobilization did not go well.

“So he thinks, now that Russia’s ranks have been thinned by Ukraine, which is a brilliant idea: why not let the North Koreans do some of the fighting?”

President Zelensky is clearly concerned about how this hostile alliance might develop.

There have been no Western boots on the ground in Ukraine for fear of escalation.

However, if reports of hundreds of North Koreans preparing to deploy are confirmed, the idea of ​​foreign boots on the ground in this war seems less concerning to Vladimir Putin.

Additional reporting by Paul Kirby, Kelly Ng and Nick Marsh.