The Pentagon says that North Korea has sent 10,000 troops to Russia, some of whom are heading for the front lines, and that the move has serious implications for the conflict and the rest of the European continent.

"We believe that the DPRK has sent around 10,000 soldiers in total to train in eastern Russia that will probably augment Russian forces near Ukraine over the next several weeks," Pentagon spokeswoman Sabrina Singh told reporters Monday, using the acronym for the repressive authoritarian state.

The news comes just days after South Korean officials told U.S. lawmakers^[1] that 3,000 North Korean troops were bound for Ukraine, while Defense Secretary Lloyd Austin told reporters^[2] during a visit to Rome that "we are seeing evidence that there are North Korean troops" who have gone to Russia but didn't offer a total.

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The Pentagon's assessment came on the same day that NATO Secretary General Mark Rutte also released a statement^[4] confirming the presence of North Korean troops in the war, which began when Russia invaded Ukraine in 2022.

Rutte said that the move is not only "a significant escalation in the DPRK's ongoing involvement in Russia's illegal war," it also violates United Nations security resolutions and represents "a dangerous expansion of Russia's war."

The relationship between Russian President Vladimir Putin and North Korean dictator Kim Jong Un has been deepening over the past year. The North Koreans had already supplied Russia with millions of rounds of ammunition and ballistic missiles before any North Korean soldiers ever stepped foot on Russian soil.

According to the NATO chief, in exchange for the troops that help Putin offset the more than half a million Russian dead or wounded that he's endured since the start of the conflict, Russia is offering North Korea "military technology and other support to circumvent international sanctions."

"Putin has failed to meet his strategic objectives and, at the end of the day, this shows ... the secretary uses this phrase ... he's 'tin-cupping' to the DPRK, Iran, because he has failed to meet those battlefield objectives," said Singh, referring to Defense Secretary Austin.

Singh told reporters that the Pentagon believes that most of the 10,000 soldiers will be training in eastern Russia but that some have already moved closer to Ukraine, and officials are "increasingly concerned that Russia intends to use these soldiers in combat or to support combat operations against Ukrainian forces in Russia's Kursk Oblast, near the border with Ukraine."

The Kursk region of Russia was invaded by Ukrainian forces in August, and they have held onto varying amounts of territory since then. While capturing the Russian territory was seen as a major, if surprising, tactical victory for the Ukrainians, it raised questions about what, if any, role it had in a broader military strategy outside of embarrassing Putin.

Ukrainian officials have argued that the intent has been to create a buffer zone between them and Russian forces, and Singh told reporters that Austin was told as late as this weekend that they intend to hold the territory. However, Austin also cautioned his Ukrainian counterparts that "there's still a significant fight in the east," referring to the contested territories of Donetsk and Luhansk.

While Singh echoed NATO's concern that the large addition of North Korea troops to the conflict has "broad implications for Europe and Indo-Pacific security," she said that the U.S. would not pressure the Ukrainians to treat them any differently, at one point calling the North Korean troops "co-belligerents."

"This is a calculation that North Korea has to make -- they are sending their soldiers into a war where we're seeing Russian casualties and losses upward of 500,000 at this point," she said.

"If they are in combat ... they're fighting the Ukrainians, who are fighting for their sovereign territory, and we've made a commitment to Ukraine that we're going to continue to support them with whatever it takes," Singh said.

Related: Ukraine's Zelenskyy Claims North Korean Troops Will Be Deployed by Russia in Coming Days^[5]