South Korean President Yoon Suk Yeol speaks during a joint press conference with Polish President Andrzej Duda (not seen in photo) at the Presidential Office in Seoul, South Korea on Thursday.

Jeon Heon-Kyun/Pool Photo/AP

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Jeon Heon-Kyun/Pool Photo/AP

SEOUL – South Korea's president vowed Thursday to respond to North Korea's troop deployment to Russia, including by possibly sending offensive weapons to Ukraine.

Seoul will not remain idle in the face of a North Korean “provocation that threatens global security beyond the Korean Peninsula and Europe,” South Korean President Yoon Suk Yeol told reporters in Seoul after a summit with visiting Polish President Andrzej Duda was.

Yoon's comments follow Defense Secretary Lloyd Austin's assertion on Wednesday that the United States has evidence of North Korea sending troops to Russia.

Austin didn't provide details about the evidence, but said if North Korean troops were fighting for Russia, it would be a “very, very serious problem.”

South Korea's intelligence chief told lawmakers on Wednesday that North Korea has sent 3,000 soldiers, including special forces, to Russia for training and that the North plans to increase that number to 10,000 by December.

The deployment of North Korean troops could heighten concerns that the war could spill over and affect tensions in Asia, from the Korean Peninsula to the Taiwan Strait.

South Korean intelligence said last week that North Korea had sent more than 13,000 containers of artillery, missiles and other conventional weapons to Russia since August 2023. Ukrainian President Volodymyr Zelensky warned earlier this month that North Korea is “no longer just about transferring weapons.” but also personnel to help the Russian armed forces.

President Yoon pledged support for further South Korean arms sales to Poland, including the $7 billion sale of K2 tanks. So far, South Korea has helped Ukraine by supplying arms to the United States and Ukraine's neighbors, but he said that could change.

“We had a policy of not supplying lethal weapons directly to combatants,” he told reporters, “but we can be more flexible and review the policy depending on North Korea's military activities.”

Even as they fight on the front lines, analysts expect North Korean troops to play only a supporting role in the war.

Lee Ho-ryung, a researcher at the Korea Institute for Defense Analyzes, a government think tank in Seoul, says North Korean troops could be sent to blunt Ukraine's offensive in Russia's Kursk region.

The North Koreans will likely be given “initial responsibility for security, etc.” But with time and training, they may be able to support Russian operations,” Lee says. “Then it is expected that there will be many victims during this process.”

South Korean Defense Minister Kim Yong-hyun told lawmakers on Thursday that North Korean troops “are viewed as mere mercenaries with cannon fodder.” North Korean leader Kim Jong Un, he added, “has sold out his people's army for an illegal war of aggression.”

North Korean state media has not mentioned the deployment of troops to Russia, and South Korean intelligence says North Korea may be seizing family members of troops sent to Russia, possibly to quell domestic discontent over the deployment.

Although the North Korean deployment has limited military value, analysts say it sends important signals to major powers.

North Korea has made Russia its top foreign policy priority and signed a treaty in June, ratified by the Russian parliament on Thursday, providing for mutual assistance if either country is attacked. The deployment of troops could be seen as cementing this agreement.

For Ukraine, the reference to North Korean intervention reinforces the Ukrainian government's appeal for Western military aid. South Korea's proposal to arm Ukraine is music to Kiev's ears, argues Yoon Sukjoon, senior research fellow at the Korea Institute for Maritime Strategy and a retired South Korean navy captain.

“South Korea's statement, 'We will now side with the United States and sell offensive weapons to Ukraine,' helps Ukraine,” he says, “and I think that's ultimately what Ukraine is doing by disclosing” the North Korean deployment wanted to achieve by President Zelensky.

However, Yoon and other analysts expect South Korea to respond cautiously to any North Korean troop deployment to deter Russia from giving North Korea the military support it demands as a reward for sending troops.

Moscow has warned Seoul not to interfere in Ukraine. “It is necessary to think about the consequences for South Korea’s security,” Russian Foreign Ministry spokeswoman Maria Zakharova said on Wednesday. “The Russian Federation will respond harshly to any steps that could pose a threat to the security of the country and its citizens.”

Se Eun Gong contributed to this report from Seoul.