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.

When Ukrainian soldiers captured two North Korean prisoners of war last month, it provided the first undeniable proof of Pyongyang’s direct involvement in the war against Ukraine