Russia presses toward Kostiantynivka as fighting reaches Ukrainian stronghold

Russian troops have pushed into the edges of Kostiantynivka, where small groups have begun probing the outskirts and Ukrainian commanders warned that close-quarters assaults could follow. The city sits at a critical hinge in eastern Ukraine’s defenses: if Moscow takes it, Russian forces would gain a foothold for a northward drive along a line that has helped hold the heavily industrialized Donetsk region.

Kostiantynivka is the southern end of Donetsk’s so-called fortress belt, a chain that also includes Sloviansk, Kramatorsk and Druzhkivka. Sloviansk and Kramatorsk form the northern half of that belt, while Druzhkivka, Oleksiyevo-Druzhkivka and Kostiantynivka make up the southern half. Ukraine has spent 11 years reinforcing the line with defensive and defense-industrial infrastructure.

The city itself has long mattered for reasons beyond the battlefield. Kostiantynivka is an industrial center and one of Ukraine’s most important glass-making cities. It had a population of 95,111 in the 2001 census, and its prewar population was nearly 70,000 before falling to around 2,000 as the front has closed in. By June 2026, Kostiantynivka had become a staging base for Ukrainian troops defending Chasiv Yar and nearby settlements.

Vladimir Putin said last week that Russia was close to capturing Kostiantynivka, part of his broader insistence that Moscow must control all of Donetsk before the war ends. Ukraine still holds roughly a fifth of Donetsk Oblast after more than four years of fighting, but Russian gains across most of the 1,200-kilometer front have largely stalled.

Ukrainian mid-range drone strikes have disrupted Russian logistics, but Emil Kastehelmi of the Black Bird conflict analysis team said the effect has not been large enough to force Russia to suspend the offensive.