Russian President Vladimir Putin claimed on Sunday that Russian forces have managed to improve their positions in Ukraine, saying they have made gains in frontline areas, such as the eastern city of Avdiivka.

"Our troops are improving their position in almost all of this area, which is quite vast," Putin told Russian TV in an interview. "This concerns the areas of Kupiansk, Zaporizhzhia and Avdiivka." 

In the past few days, Russia has intensified its attacks on Avdiivka, which lies in the eastern Donetsk province.

"What is happening now along the entire length of the [line of] contact is called 'an active defense'," he said.

mm, rmt/wd (Reuters, AP, AFP, dpa)