About 11000 North Korean soldiers are being trained in Russia ...

North Korea allegedly sending soldiers to Russia would create a new dimension to the war in Ukraine, an expert says.

It comes after Ukrainian officials released a video that purports to show dozens of North Korean soldiers, who they say were being introduced into the conflict, collecting Russian military uniforms.

Here's what we know.

Before footage emerged, South Korea's National Intelligence Service said the neighbouring state had sent about 1,500 soldiers to Russia to fight in Ukraine.

The head of Ukraine's military intelligence, Kyrylo Budanov, later claimed in local media that about 11,000 North Korean soldiers were currently training in eastern Russia.

It came after the video released by Ukrainian officials, which allegedly showed North Korean soldiers standing in line to pick up bags, clothes and other items from Russian soldiers.

It was published by Ukraine's Center for Strategic Communications and Information Security, which operates under the Culture and Information Ministry.

The centre claims a Russian soldier shot the footage in recent days but it did not say how the footage was obtained. The location of where the vision was taken was also unknown.

"We received this video from our own sources. We cannot provide additional verification from the sources who provided it to us due to security concerns," Ihor Solovey, the head of the centre, said.

"For Ukraine, this video is important because it is the first video evidence that shows North Korea participating in the war on the side of Russia. Now not only with weapons and shells but also with personnel."

University of Sydney's Olga Boichak, who is the editor of Digital War, said it was unprecedented that North Korean soldiers appeared to be fighting in Europe.

"This is a significant escalation of this war," she said.

"Perhaps the previous escalation was when Iran gave a range of weapons to Russia, particularly the Shahed [kamikaze] drones.

"That was already an involvement of Russia's ally in this conflict, and now we're seeing another ally, North Korea, being involved by supplying troops."

There was a larger significance, according to Dr Boichak, to North Korea's reported decision to send soldiers to Russia.

In July, Hungary extended its national card immigration program to include Russians and Belarusians, which gives those access to work in the country without security clearance.

"The benefit that North Korea would get from this is having its soldiers disguised as Russian soldiers. It has an unprecedented ability to infiltrate the EU states," she said.

"Because we know that a few months ago, Hungary had eased border crossing conditions for Russian and Belarusian passport holders."

Australian National University's Ron Huisken, who specialises in strategic and defence studies, said this was an example of North Korea showing the world that they were changing their political stance of isolation.

"It crosses a bridge that adds a new dimension to the Ukraine war," Dr Huisken said.

The reports could be the first indication of the new pact signed between Russia and North Korea earlier this year. (AP: Mikhail Metzel, Sputnik)

But he said that was not without danger.

"If North Korean combat troops are allowed to play any role, that inescapably gives a licence to the opponents, to Ukraine, to do something similarly," he said.

"They're not creating new waves by taking that step, if Russia and North Korea take it first. And that puts the question of, 'Can we use the equipment we have already received to its full potential?'

"These kinds of things incrementally widen the global footprint of the invasion of Ukraine, and make it slightly more likely that it may escalate and involve more people more directly."

In June, North Korean leader Kim Jong Un and Russian President Vladimir Putin signed a pact stipulating mutual military assistance if either country was attacked.

It followed Mr Kim's visit to Russia in 2023.

The new agreement was signed after Mr Putin's first visit to North Korea in 24 years.

At the time, Mr Kim said relations between the two countries were entering a new era of "blossoming", according to Russian news agencies.

"Which cannot be compared even with the period of Korean-Soviet relations of the last century," he said.

Mr Putin also said at the time that he appreciated North Korea's "systematic and permanent support" of Russian policy, specifically referencing the war in Ukraine.

Peter Zalmayev, Director of the Eurasia Democracy Initiative in Ukraine, said the sending of troops was an indication of the agreement signed between Russia and North Korea.

"It's still unclear as to their fighting ability," he told RN Breakfast.

"They probably don't speak Russian, so it would be difficult to understand how they would be integrated into the military command, where there would be a separate fighting unit, and what their motivation would be."

ABC/Wires