Brussels. North Korea has sent about 10,000 troops to Russia to train and fight in Ukraine within “the next several weeks,” the Pentagon said Monday, in a move that Western leaders say will intensify the almost three-year war and jolt relations in the Indo-Pacific region.

Some of the North Korean soldiers have already moved closer to Ukraine, Pentagon spokeswoman Sabrina Singh said, and were believed to be heading for the Kursk border region, where Russia has been struggling to push back a Ukrainian incursion.

Earlier Monday, NATO Secretary-General Mark Rutte confirmed recent Ukrainian intelligence reports that some North Korean military units were already in the Kursk region.

Adding thousands of North Korean soldiers to Europe’s biggest conflict since World War II will pile more pressure on Ukraine’s weary and overstretched army. It will also stoke geopolitical tensions in the Korean Peninsula and the wider Indo-Pacific region, including Japan and Australia, Western officials say.

Russian President Vladimir Putin is keen to reshape global power dynamics. He sought to build a counterbalance to Western influence with a summit of BRICS countries, including the leaders of China and India, in Russia last week. He has sought direct help for the war from Iran, which has supplied drones, and North Korea, which has shipped large amounts of ammunition, according to Western governments.

Rutte told reporters in Brussels that the North Korean deployment represents “a significant escalation” in Pyongyang's involvement in the conflict and “a dangerous expansion of Russia’s war.”

US Defense Secretary Lloyd Austin and Secretary of State Antony Blinken will meet with their South Korean counterparts later this week in Washington.

Singh said Austin and Defense Minister Kim Yong-hyun will discuss the deployment of North Korean soldiers in Ukraine. There will be no limitations on the use of U.S.-provided weapons on those forces, Singh said.

“If we see DPRK troops moving in towards the front lines, they are co-belligerents in the war,” Singh said, using the acronym for the Democratic People's Republic of Korea, or North Korea. “This is a calculation that North Korea has to make.”

Russia’s Foreign Minister Sergey Lavrov shrugged off Rutte’s comments and noted that Pyongyang and Moscow signed a joint security pact last June. He stopped short of confirming North Korean soldiers were in Russia.

Lavrov claimed that Western military instructors long have been covertly deployed to Ukraine to help its military use long-range weapons provided by Western partners.

Ukraine, whose defenses are under severe Russian pressure in its eastern Donetsk region, could get more bleak news from next week’s US presidential election. A Donald Trump victory could see key US military help dwindle.

In Moscow, the Defense Ministry announced Monday that Russian troops have captured the Donetsk village of Tsukuryne -- the latest settlement to succumb to the slow-moving Russian onslaught.

Rutte spoke in Brussels after a high-level South Korean delegation, including top intelligence and military officials as well as senior diplomats, briefed the alliance’s 32 national ambassadors at NATO headquarters.

Rutte said NATO is “actively consulting within the alliance, with Ukraine, and with our Indo-Pacific partners,” on developments. He said he was due to talk soon with South Korea’s president and Ukraine’s defense minister.

“We continue to monitor the situation closely,” he said. He did not take questions after the statement.

Ukrainian President Volodymyr Zelensky, citing intelligence reports, claimed last Friday that North Korean troops would be on the battlefield within days.

He previously said his government had information that some 10,000 troops from North Korea were being readied to join Russian forces fighting against his country.

Days before Zelensky spoke, American and South Korean officials said there was evidence North Korea had dispatched troops to Russia.