Ukraine said Thursday that its troops lost control over two settlements in the eastern Donbas region where it is fighting fiercely to retain control of the twin cities of Severodonetsk and Lysychansk.

"We lost control over Loskutivka and Rai-Oleksandrivka," said the Lugansk regional governor, Sergiy Gaiday, referring to two hamlets south east of Lysychansk.

Their capture puts Russian troops deeper in the Donbas region where they appear closer to encircling the two urban hubs which are separated by the Donets river. 

Gaiday added that Russian forces were working to capture Severodonetsk, an industrial town with a pre-war population of around 100,000 where Ukrainian and Russian troops have been fighting in a brutal standoff for weeks.

He said Moscow's army was "conducting offensive operations to encircle our troops in the Lysychansk area, and are blocking the Lysychansk-Bakhmut route," a key lifeline out of the embattled area. 

"Severodonetsk is being destroyed, all positions of our forces are shelled around the clock," he said.

The Russians are "storming Syrotyne," he added, referring to a settlement directly adjacent to Severodonetsk's southern edges.