Since then, Russian forces – bolstered by thousands of North Korean troops sent by Putin-ally Kim Jong-un – have sought to claw back most of that land. The North Korean troops began arriving in Kursk from late October as part of a mutual defence pact agreed between Putin and Kim.

After clinging for more than seven months to a gradually shrinking area, Ukraine has seen its position worsen sharply in the past week.

Dressed in military fatigues for a surprise visit to soldiers in the Russian region of Kursk on Wednesday, President Vladimir Putin ordered his forces to swiftly recapture the rest of the area