US officials have claimed that North Korea is suffering mass casualties on the front lines of Russia’s war against Ukraine, being used in costly “human wave” attacks. White House spokesperson John Kirby told reporters on Friday that thousands of North Korean troops had been killed or wounded in the last week alone.

"Through various sources of information and intelligence, we assess that North Korean troops who have recently engaged in combat with Ukrainian forces have suffered around 1,100 casualties," the JCS said in a statement.