North Korean leader Kim Jong Un has paid an emotional tribute to soldiers who have died fighting for Russia in its war against Ukraine, saying his ‘heart aches’ in a rare admission of military losses.

North Korean leader Kim Jong Un held a ceremony to honor the country's troops deployed to Russia, state media reported Friday, calling them "great heroes and great patriots."

The newly-tested air-defense missiles "are very suitable for destroying various aerial targets," North Korean state media reported.