North Korea allegedly provided more troops to Russia for support in their war in Ukraine, according to South Korea’s spy agency. South Korea’s National Intelligence Service announced it detected new troop movements from North Korea but did not specify how many troops have been deployed to Russia recently.

The fresh deployment comes after North Korea suffered heavy casualties on the front lines in Russia’s war against Ukraine, the South’s spy agency says.

South Korean officials say Kim Jong-un will struggle to explain loss of life, with estimates suggesting 300 of country’s troops killed

South Korea’s spy agency said Thursday that North Korea appears to have sent additional troops to Russia, after its soldiers deployed on the Russian-Ukraine fronts suffered heavy casualties. The National Intelligence Service said in a brief statement it was trying to determine exactly how many more troops North Korea has

On Monday, the U.S. joined North Korea, Iran and 15 other countries in voting against a U.N. General Assembly resolution drafted by Ukraine that blamed Russia for the “devastating and long-lasting” war; the resolution passed with 93 votes in favor.

Ukrainian troops holding positions in Kursk say the North Koreans have reappeared on the battlefield and become even more formidable foes.