Explainer-What we know about North Korean forces joining Russia's war against Ukraine

North Korea has moved beyond weapons shipments to send troops and a missile unit to Russia to back the war in Ukraine—reports say a unit of roughly 90 personnel with dozens (up to 120) of ballistic missiles has deployed to western Russia.
Pyongyang has already supplied massive quantities of arms to Moscow—analysts report millions of artillery shells and hundreds of ballistic missiles delivered by ship—helping sustain Russian forces on the front.
This is Pyongyang’s most significant wartime role since the 1950s, deepening Russia–North Korea ties and prompting U.S./ally sanctions and wider international concern about regional and global security.