North Korean leader Kim Jong Un has returned from his visit to Russia, where he met with President Putin to strengthen ties and discuss defense cooperation. Concerns have been raised about potential arms transfers that would violate UN resolutions. Kim's visit to munitions factories before the trip has led to speculation about arms production for shipment to Russia. Kim expressed support for Putin and discussed expanding coordination between their armed forces. Kim is considering supplying ammunition to Russia in exchange for nuclear weapons technology, and the US and South Korea have warned that such deals would violate UN resolutions.