Seoul, South Korea CNN  — 

There is growing intelligence that North Korea has been readying itself for a more direct role in Russia’s war in Ukraine, a move that could reverberate far beyond the frontlines of the war raging in Europe.

The United States, Ukraine and South Korea say that North Korean troops were dispatched to Russia for training with the aim of being deployed to Ukraine.

Russia and North Korea have dismissed the reports, although on Thursday at the BRICS summit, Russian President Vladimir Putin did not deny that Pyongyang had sent soldiers to the country.

South Korea has hinted that any deployment could cause it to reassess what level of military support it gives Ukraine.

A group of North Korean soldiers has been spotted in Russia’s Kursk region, an area that borders Ukraine and has seen ongoing military operations, Ukraine’s military intelligence service announced Thursday.

Leaked audio intercepts obtained by the Defense Intelligence of Ukraine and released on Friday revealed Russian soldiers raising concerns about how North Korean soldiers will be commanded and provided with ammunition and military kit, further heightening fears around Pyongyang’s involvement.

In recent months, Moscow and Pyongyang have deepened their anti-US military partnership and the growing alliance has concerned officials in Kyiv and Washington.

Here’s what we know.

Are North Koreans in Ukraine?

On Wednesday, the White House said at least 3,000 North Korean soldiers had arrived in eastern Russia this month and while it remains unclear what they will do, it is a “highly concerning probability” that they will join the fight against Ukraine.

Ukrainian President Volodymyr Zelensky has repeatedly warned that North Korean troops are joining Russia’s war, telling a NATO summit last week that “10,000” soldiers and technical personnel were being prepared.

Zelensky said Friday that according to Ukraine’s intelligence, Russia will deploy its first North Korean troops in combat zones on October 27 and 28, adding, “This is a clear step in Russia’s escalation that matters.”

Inna Varenytsia/Reuters
A view of a damaged residential buildingin the front line city of Chasiv Yar in Donetsk region, Ukraine, on October 16, 2024.

Meanwhile, South Korea’s spy agency, the National Intelligence Service (NIS), said last week that North Korea had shipped 1,500 soldiers, including special forces fighters, to Russia for training.

Those reports appeared to be bolstered when North Korean soldiers were filmed receiving uniforms and equipment at a training ground in Russia’s Far East. Another video circulating on social media and geolocated by CNN showed troops arriving at the Sergeevka Training Ground close to Russia’s border with China.

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What is Ukrainian intelligence saying?

The Defense Intelligence of Ukraine said Thursday that some North Korean troops, who had received training in Russia’s far east, have made their way to the Kursk region in western Russia, where Ukraine has maintained a foothold since launching a surprise incursion in August.

Russian soldiers have been heard raising concerns about how North Korean soldiers will be commanded and provided with ammunition and military kit, leaked intercepts obtained by the Defense Intelligence of Ukraine and released on Friday show.

The Russian soldiers talk disdainfully about the incoming North Korean soldiers, codenamed the “K Battalion,” at one point referring to them as “the f**king Chinese.”

In the same extract, a serviceman describes another who has been tasked to “meet people.”

“And he’s like standing there with his eyes out, like… f**k,” the soldier says. “He came here and says what the f**k to do with them.”

The audio was intercepted from encrypted Russian transmission channels on the night of October 23, according to Ukraine’s Defense Intelligence.

Ukraine’s analysis of the intercepts revealed that North Korean troop movements were planned for the morning of October 24, in the area of Postoyalye Dvory field camp in the Kursk region.

The intercepts also reveal plans to have one interpreter and three senior officers for every 30 North Korean men, which the Russian soldiers are heard in the audio condemning.

“The only thing I don’t understand is that there [should be] three senior officers for 30 people. Where do we get them? We’ll have to pull them out,” one Russian serviceman says.

What’s North Korea’s relationship with Russia?

Russia and North Korea, both pariahs in the West, have forged increasingly friendly ties since Moscow’s invasion.

In June, the two nations signed a landmark defense pact and pledged to use all available means to provide immediate military assistance in the event the other is attacked.

Multiple governments have accused Pyongyang of supplying arms to Moscow for its grinding war in Ukraine, a charge both countries have denied, despite significant evidence of such transfers.

KCNA/AP
North Korean leader Kim Jong Un and Russia's President Vladimir Putin after signing a comprehensive strategic partnership in Pyongyang, North Korea on June 19, 2024.

The arms shipments, which include thousands of metric tons of munitions, have helped Russia replenish its dwindling stockpiles in a war where Ukraine’s forces have long been outgunned and outmanned. Meanwhile, cash-strapped North Korea is believed to have received food and other necessities in exchange.

The hermit nation also seeks to advance its space, missile and illegal nuclear programs.

What has the reaction been?

The Kremlin had initially dismissed allegations of North Korean troop deployments, but on Thursday at the BRICS summit, Putin did not deny that Pyongyang had sent soldiers to the country.

Kremlin spokesman Dmitry Peskov previously dismissed the allegations that North Korean personnel had been sent to help Russia as “another hoax.” When asked directly by reporters on Monday whether Moscow was sending North Korean troops to fight in Ukraine, Peskov said that North Korea is a “close neighbor” and the two states were “developing relations in all areas.”

“This cooperation is not directed against third countries,” he said.

North Korea called the claims “groundless, stereotyped rumors,” during a UN General Assembly meeting Monday.

But Seoul is not taking this lightly.

On Monday, its Foreign Ministry summoned the Russian ambassador and urged an “immediate withdrawal of North Korean troops.”

François Walschaerts/AFP/Getty Images
Ukraine's President Volodymyr Zelensky during a press conference at the NATO headquarters in Brussels, on October 17, 2024.

South Korean First Vice Minister of Foreign Affairs Kim Hong-kyun warned the alleged deployment violates UN Security Council resolutions. The National Security Office held an emergency meeting to discuss a possible South Korean response.

Following the meeting, Kim Tae-hyo, the first deputy director of national security, said the government would implement “phased countermeasures” according to the “progress of the military cooperation between Russia and North Korea.”

It is unclear what the measures would be, but a South Korean government official said that they are preparing “diplomatic, economic and military measures.”

As North Korea is in the “preliminary stage of deploying troops to Russia,” South Korea is assessing whether it will proceed to “actual combat participation,” the government official added.

“We are developing scenarios to understand the potential impacts North Korea and Russia’s actions could have on us,” the government official said.

Seoul, one of the world’s largest arms suppliers, has provided humanitarian aid and financial support to Ukraine, while joining Western sanctions against Moscow. But it has has not directly provided lethal weapons to Kyiv due to arms export controls to countries at war.

The stakes are high.

North and South Korea are separated by one of the world’s most militarized borders and remain technically in a state of war. Relations between the two have deteriorated in recent years with an uptick in fiery rhetoric on both sides of the demilitarized zone.

Secretary of Defense Lloyd Austin said Wednesday the US does not believe the North Korean troops have reached Ukraine, but the movements have generated deep concern as a potentially serious escalation. “It will have impacts not only in Europe. It will also impact things in the Indo-Pacific as well,” Austin said.

National Security Council spokesman John Kirby said if the troops are deployed to Ukraine, “They’re fair game. They’re fair targets.”

What’s the significance?

Any intervention by North Korea could be a watershed moment. The isolated and heavily sanctioned regime taking a role in a major international conflict on the other side of the world is something it has not done in decades.

The state has one of the largest militaries in the world, with 1.2 million soldiers, but many of its troops lack combat experience.

Analysts say the North Korean regime would have a lot to gain from deploying troops, including giving its forces battlefield experience and technical training. The arrangement could also help North Korea gain real-world intelligence on the functioning of its weaponry.

“The special forces troops will come back with live battlefield experience, live infiltration experience against an alerted combat opponent. That makes them more dangerous,” said Carl Schuster, former director of operations at the US Pacific Command’s Joint Intelligence Center.

Ng Han Guan/AP/File
Soldiers march in a parade for the 70th anniversary of North Korea's founding day in Pyongyang, North Korea, on September 9, 2018.

“I think Kim is providing the troops to gain the resources he needs to sustain the regime, and lessons learned that he might apply if he thinks the conflict is coming in the peninsula,” he added.

Chun In-bum, a former lieutenant general in the South Korean army, told CNN that the Russians would “get a boost in manpower, which they lack right now” and the North Koreans will get “money, technology” and experience.

Those deployed would be special “elite” forces rather than conventional troops, analysts say.

“If they succeed there, they will get not only firsthand battle experience, but international recognition. So, this could be a real serious problem for the entire world,” Chun said.

“What if the North Koreans make this a habit? What if they become a base for supplying well-trained soldiers? The potential of this deployment should be very concerning.”

CNN’s Paul P. Murphy contributed to this report.