Ukraine's military is inflicting "extraordinarily significant" losses on Russian forces near the town of Vuhledar in the eastern Donbas region, President Volodymyr Zelenskyy said on Sunday.

"The situation is very complicated. And we are fighting. We are breaking down the invaders and inflicting extraordinarily significant losses on Russia," Zelenskyy said in his nightly video address.

Zelenskyy referred to several towns in Donbas, where fighting has been focused for months, saying "the more losses Russia suffers there, in Donbas — in Bakhmut, Vuhledar, Marinka, Kreminna — the faster we will be able to end this war with Ukraine's victory."

Zelenskyy outlined the state of defense in other sectors after what he described as an "extended" meeting of the military command.

Matters were under control near the Black Sea port of Odesa, he said, and troops were "protecting" the central region of Zaporizhzhia, partly controlled by Russian forces.

There were "very good results" on the northern border with Russia and its ally Belarus, areas where Ukrainian troops retook cities from Russian forces in September and October.

"Of course, military issues and intelligence details are not something you can share with everyone," Zelenskyy said. "But I want our people to have predictability right now. And a sense that Ukraine is moving towards its goals."