As Ukrainian forces report progress in reclaiming territory in eastern and southern regions, Russian President Vladimir Putin has released a video message that appears to provide justification for occupying parts of Ukraine.

Ukraine's military said on Friday that its counteroffensive is continuing in the southern region of Zaporizhzhia, where troops have reportedly breached Russia's first line of defense and are headed toward the key city of Melitopol.

This follows their reported recapture of Robotyne late last month, marking notable territorial gains in the south.

Military officials also said that in the eastern region of Donetsk, Ukrainian troops have repelled Russian forces south of the major battle area of Bakhmut.

Ukrainian authorities say Russia is continuing to wage attacks against non-military targets.

They say a police building was attacked on Friday in Kryvyi Rih in the eastern region of Dnipropetrovsk, leaving one police officer dead and 44 others wounded.

On Wednesday, a Russian strike killed 17 people in a market in Kostiantynivka in the Donetsk region.

In Russia, President Putin released a video message on Friday, marking the 80th anniversary of "the Soviet Union's liberation of the Donbas region" in eastern Ukraine from Nazi Germany during World War Two.

Asserting that Donbas has been a base for Russia for many centuries, Putin emphasized the region was freed from the Nazis after roughly 700 days of resistance.

Observers suggest Putin aims to use this narrative to justify the Ukrainian occupation and bolster patriotism during the prolonged military operation.