Western officials have told the BBC that North Korean troops have already suffered nearly 40% casualties in the fighting in Russia's western Kursk region, in just three months.

Ukraine's military said 21 troops were killed and 40 injured in the operation in the Russian region where it is staging an incursion.

The report highlights that North Korean soldiers have developed unique battlefield tactics, such as using a soldier as bait to shoot down drones or detonating grenades, holding it under the neck with one hand on the pin when the Ukrainian military approaches to avoid capture when severely wounded.