Though North Korean ballistic missiles account for only a small portion of Russia's missile strikes they carry a large warhead of up to one tonne and have a range of up to 800 km, the military source said. The Iskander-M, an equivalent Russian missile, carries a smaller payload and has a shorter range of 500 km.

North Korean ballistic missiles fired at Ukraine by Russian forces since late December have been far more precise than salvos of the weapons launched over the past year, two senior Ukrainian sources told Reuters.

North Korean soldiers had been missing from combat, fueling speculation they were pulled back after taking heavy losses.

North Korean ballistic missiles have been striking targets in Ukraine with increasing accuracy in recent weeks compared to over the past year — suggesting the Hermit Kingdom is using the battlefield as a testing ground for its new tech.

This is almost certainly primarily due to heavy losses sustained during attacks against Ukrainian-held positions.” Reports differ on the scale of the losses but one put them as high as 4,000 North Korean soldiers killed or wounded.

North Korean missiles used by Russia in attacks on Ukraine since December have become more accurate, Reuters reported on Feb. 6, citing sources familiar with the matter. Analysts believe North Korea is using the battlefield as a testing ground for its missile technology,