Ukraine's military said on Thursday its troops were in full control of the northeastern Ukrainian city of Kupiansk and that their forces had stopped a Russian advance towards the railway hub.

A Russian-installed official said earlier that Moscow's forces were gaining a foothold on the outskirts of the city, more than 2½ years since Russia launched its full-scale invasion.

Kupiansk was seized by Moscow's forces in the early days of their February 2022 invasion and recaptured by Ukrainian troops in a rapid counter-offensive months later. In recent months, the area has seen an upsurge of activity by Russian forces.

"The alleged presence of Russian troops in the city of Kupiansk is not true," the Ukrainian military's General Staff wrote on the Telegram messenger.

Reuters could not independently verify the battlefield accounts.