North Korean troops reportedly deployed in Ukraine, prompting U.S. and allies' concern over escalating tensions with Russia.

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.

The war between Russia and Ukraine is intensifying with new attacks and new concerns over the weapons being used by both sides. Vladimir Putin says Russia’s use of a nuclear-capable weapon is a response to Ukraine firing American weapons deeper into Russia for the first time.