SEOUL — South Korea’s president vowed on Thursday to respond to North Korea’s deployment of troops to Russia, including by potentially supplying offensive weapons to Ukraine.

Seoul will not “sit 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 meeting with visiting Polish President Andrzej Duda.

Yoon’s remarks follow Defense Secretary Lloyd Austin’s assertion Wednesday that the United States has evidence of North Korea’s deployment of troops to Russia.

Austin did not specify what the evidence was, but said if North Korean troops were to fight for Russia, it would be a “very, very serious issue.”

South Korea’s intelligence chief told lawmakers Wednesday that North Korea has sent 3,000 troops, 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 add to concerns that the war risks spilling over and affecting tensions in Asia, from the Korean Peninsula to the Taiwan Strait.

South Korea's intelligence agency 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 Zelenskyy warned earlier this month that North Korea is "no longer just about transferring weapons" but personnel too to help Russian forces.

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

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

Even if they do fight on the front lines, analysts believe North Korean troops will be relegated to a supporting role in the war.

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

The North Koreans will likely be put “in charge of security and such at first. But as time goes by, and with training, they may be able to support Russian operations,” Lee says. “Then, it is expected that there will be many casualties during that process.”

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

North Korean state media have made no mention of deploying troops to Russia, and the South’s intelligence agency says North Korea may be sequestering family members of troops sent to Russia, possibly to quell domestic discontent at the deployment.

Even if the North Korean deployment has limited military value, analysts say it sends important messages to major powers.

North Korea has named Russia as its top foreign policy priority, and in June, signed a treaty, ratified by Russia’s parliament on Thursday, which allows for mutual assistance if either country comes under attack. Deploying troops could be seen as cementing that deal.

For Ukraine, pointing to North Korean intervention strengthens the Ukrainian government's appeals for Western military aid. South Korea’s suggestion that it could arm Ukraine is music to Kyiv’s ears, argues Yoon Sukjoon, a senior research fellow at the Korea Institute for Maritime Strategy, and a retired South Korean navy captain.

"South Korea saying: 'We will now stand on the U.S. side and sell offensive weapons to Ukraine' helps Ukraine,” he says, “and I think that's ultimately what Ukraine wanted to get from President Zelenskyy's disclosure” of the North Korean deployment.

That said, Yoon and other analysts believe South Korea will respond cautiously to any North Korean troop deployment, to keep Russia from giving North Korea the military assistance that it seeks as a reward for sending troops.

Moscow has warned Seoul not to get involved in Ukraine. "It is necessary to think about the consequences for the security of South Korea" if it entered the conflict in Ukraine, Russian Foreign Ministry spokesperson Maria Zakharova said Wednesday. "The Russian Federation will react harshly to any steps that may pose a threat to the security of the country and its citizens."

Se Eun Gong contributed to this report from Seoul.

Copyright 2024 NPR