Ukrainian President Volodymyr Zelensky confirmed Monday more than 3,000 troops from North Korea have been killed so far fighting next to Russian forces.

Secretive North Korea has one of the world’s largest militaries, with 1.28 million active soldiers, but unlike in Russia, the Korean People's Army (KPA) has no recent experience of combat. Pyongyang’s army is “thoroughly indoctrinated but with low readiness,” says Mark Cancian, from the Centre for Strategic and International Studies (CSIS).

North Korean soldiers fighting for Russia were given fake military documents with Russian names and birthplaces, the Ukrainian military said, amid claims from Kyiv that Russia is trying to conceal the presence of foreign fighters on the battlefield.