Ukrainian counter-offensive in north-east inflicts a defeat on Moscow

In developments unforeseeable just a few days ago, Russian officials said troops would be moved from the Balakliia and Izium areas to help its operation in Donbas, mirroring the justification the Kremlin gave for withdrawing its forces from the Kyiv region soon after the start of the seven-month war.

In a video address on Saturday the president, Volodymyr Zelenskiy, said Ukrainian forces had liberated about 2,000 sq km (700 square miles) of territory since the counter-offensive against Russia started earlier this month.

Izium has for centuries been regarded as the gateway to the Donbas region of eastern Ukraine and, from there, to the Black Sea. The Russians called the area around it Izium passage.

Kuzan said the Russian formations in charge of the south-east area of Kharkiv, labelled the Izium area by military experts, were professional Russian soldiers, not mercenaries or conscripts from Russian-occupied Donbas.

The capture of Kupiansk potentially leaves thousands of Russian soldiers trapped at the frontline and cut off from supplies.

According to the Ukrainian military, Russia is also sending 1,300 Chechen fighters to the southern Kherson region.

It comes as western intelligence suggests that Russian forces in Kherson are coming under sustained pressure from Ukrainian attacks.

Agence France-Presse, the Associated Press and Reuters contributed to this report