North Korean troops have not been seen on the frontlines in Russia’s Kursk region for several weeks, a Ukrainian military official said Friday, amid reports of mass casualties among Pyongyang’s forces.

North Korea sent its best troops to aid Russia in its war against Ukraine. But after months of suffering severe losses, they have been taken off the front line.

North Korean troops are no longer fighting on Russia’s behalf in Vladimir Putin’s war against Ukraine, according to reports. Pyongyang signed a mutual defence agreement with Moscow last year, promising to defend one another if a third party were to attack.