Soldiers fighting for Ukraine describe facing relentless waves of determined North Korean troops, Russian units with improved tactics, and Ukraine’s own struggles with exhaustion and sinking morale.

North Korea has not responded to reports of its troops captured or killed by Ukraine forces. It has never publicised the deployment or large shipments of North Korean artillery shells and other weapons sent to Russia to help its war against Ukraine, although they marked the country’s first intervention in a major armed conflict overseas in decades.

British intelligence has reported that one-third of the troops deployed alongside Russian forces in Ukraine are already out of action. Pyongyang sent a contingent of 12,000 soldiers to Russia to assist local forces in regaining lost territory in the Kursk region,