The U.S. and its allies are “alarmed” by North Korea’s nuclear and missile threats as well as its increasing military support for Russia’s war in Ukraine, a senior U.S. official said Wednesday, but couldn’t confirm Ukrainian claims that North Korean soldiers were sent to fight for Moscow.

Ukraine called on its allies on Wednesday to impose new sanctions on Pyongyang after it said North Korea had become a de facto participant in the war in Ukraine on Russia's side. President Volodymyr Zelenskiy told parliament in a speech to outline his victory plan that his spy services had confirmed North Korea's supply of both weapons and people to Russia,