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.

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 troops have been pulled back from the frontline amid devastating losses, according to Ukrainian and American officials. Kim Jong Un ’s forces have not been seen on the battlefield for around three weeks, Ukrainian special forces said, according to the New York Times.

North Korean troops seem to temporarily withdraw from one section of front in Kursk Oblast, military says Russia claims to capture Velyka Novosilka, Ukraine admits partial retreat but says battles ongoing Russia intensifies attacks near Pokrovsk,

North Korean troops, largely special ops forces, have suffered high casualties in bloody assaults not unlike other units, including prison units.

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.