Additionally, Nato chief Mark Rutte called the troop deployment “a dangerous expansion of Russia’s war” and “a sign of Putin’s growing desperation”.
Rutte noted more than 600,000 Russian soldiers have been killed or wounded since the conflict started in 2022, adding the Kremlin was unable to sustain the invasion without foreign support.
Despite the cost, Russia has been making steady territorial gains in Ukraine.
Moscow’s army advanced 478 square kilometres into Ukrainian territory in October, a record since the first weeks of the war, according to an AFP analysis of data from the Institute for the Study of War.
By October 27, Russian forces had gained more territory than in August and September 2024 (477 and 459sq km respectively) amid major shifts on the front line, in particular in eastern Ukraine around Pokrovsk.
Growing threats
Speaking in Brussels after a briefing with South Korean intelligence officials, Rutte said he could confirm North Korean military units had been deployed in the field in Russia’s western Kursk region.
Ukrainian troops launched a ground offensive in Kursk in August and control several hundred square kilometres of Russian territory.
“The deepening military co-operation between Russia and North Korea is a threat to both the Indo-Pacific and Euro-Atlantic security,” Rutte told reporters in Brussels.
Experts have said in return for the troops, North Korea is likely aiming to acquire military technology, ranging from surveillance satellites to submarines, plus possible security guarantees from Moscow.
EU chief Ursula von der Leyen also warned that North Korea sending troops “for the first time” represented “a significant escalation of the war against Ukraine and threatens global peace”.
She made the comments after a phone call with South Korean President Yoon Suk Yeol, during which she assured the leader “the EU’s response to this development will centre on co-operation with the Republic of Korea and other like-minded partners”.
‘Enemy understands strength’
Last week, Ukrainian President Volodymyr Zelenskyy warned Russia was planning to send North Korean troops into battle within days.
“This is an escalation. Sanctions alone are not enough. We need weapons and a clear plan to prevent North Korea’s expanded involvement in the war in Europe,” Zelenskyy’s chief of staff Andriy Yermak said on social media on Monday after Rutte’s comments.
“Today, Russia brings in North Korea; next, it could broaden their engagement, and then other autocratic regimes may see that they can get away with this and come to fight against Nato,” he warned.
“The enemy understands strength. Our allies have this strength.”
Rutte, a former Dutch prime minister who took over the reins of Nato this month, called on Moscow and Pyongyang to “cease these actions immediately”.