North Korea is expanding a weapons plant that manufactures missiles used by Russia against Ukraine, according to new research from a US-based think tank.

The Ukrainian military said on Monday that it found Western-made parts inside North Korean ballistic missiles, marking the latest discovery for Kyiv as it continues to find technology from Europe and the US inside weapons used by the Russian military.

"Right now, they (Ukrainian soldiers) have the ability to use ATACMS to defend themselves in an immediate-need basis. Understandably, that's taken place in and around Kursk Oblast," U.S. National Security Council spokesperson John Kirby told journalists on Nov.