Putin has amassed 50,000 soldiers including North Korean troops in Kursk ahead of counteroffensive
Putin could begin the combined assault with Kim Jong-un's troops sent to fight in just days, Ukrainian officials have told the New York Times.
US and Ukrainian officials say 10,000 of the 50,000 massed troops are North Koreans.
Those soldiers are said to be wearing Russian uniforms and have been equipped by Moscow, but will fight in their own units.
Putin's army has also been training the North Koreans in infantry tactics, artillery fire, and trench clearing.
