Russia is believed to have transported tens of thousands of North Korean soldiers to the front lines by rail and air.

"Today I can confirm that over 10,000 (North Korean) soldiers have been sent to eastern Russia, and most of them have moved to the far western Kursk Oblast, where they have begun engaging in combat operations with Russian forces,

Russia attacked the Ukrainian capital Kyiv with a sophisticated combination of missiles and drones for the first time in 73 days on Wednesday, authorities reported, as the Pentagon said most of the North Korean troops sent to help Moscow's war effort are fighting to drive Ukraine's army off Russian soil in the Kursk border

The cash-strapped North Korean leader has sent some 10,000 troops to help in Russia’s war against Ukraine. Moscow could be giving him money and nuclear know-how.

Ukraine’s defense minister says Ukrainian troops have engaged for the first time with North Korean units that were recently deployed to help Russia in the war with its neighbor.

Nearly all would raise their hands to go, ex-military defectors explain, owing to regime loyalty, promise of higher status and a glimpse of the outside world.

The presence of North Korean soldiers alongside Russians fighting Ukraine raises many tactical and military questions, leading some analysts to wonder about their effectiveness and ultimate objectives.