“Our troops are improving their position in almost all of this area, which is quite vast,” he said in an interview on Russian television, an extract of which was posted on social media today.

“This concerns the areas of Kupiansk, Zaporizhzhia and Avdiivka.”

Yesterday, Kyiv reported “heated” fighting around Avdiivka, saying Russian forces had “not stopped assaulting” it for days in their attempt to surround it.

Ukraine last week said Russia had stepped up assaults on the frontline city, which lies just 15km from Moscow-held Donetsk.

Avdiivka has been a symbol of Ukrainian resistance since 2014, after it briefly fell to Russian-backed separatists.

Russian forces now control territory to the east, north and south of Avdiivka.

Some 1,600 civilians are believed to be in the city, which had a pre-war population of 31,000.

Ukrainian president Volodymyr Zelensky had said Kyiv was holding its ground in Avdiivka, but Moscow has previously claimed its positions had improved there.