DONETSK REGION — Russian forces lost a net 116 square kilometres of territory in Ukraine's Donetsk region during April 2026, according to assessments tracking the front line. The calculation counted only territory firmly held and excluded contested areas where both Russian and Ukrainian soldiers held positions.

The Institute for the Study of War said Russian forces have been using infiltration tactics to create the perception of continuous advances and to support Kremlin cognitive warfare efforts that exaggerate battlefield successes. The institute said forces do not control infiltration areas, and observed that the rate of advance has slowed by at least two-thirds over the past 18 months.

Forces seized an average of 2.9 square kilometres per day in the first third of 2026, compared with an average of 9.76 square kilometres per day during the same period in 2025. The Russian military claimed to be gradually overrunning Kostiantynivka, but the Institute for the Study of War observed that forces had infiltrated 10.14 percent of the city and advanced in only 0.7 percent of its eastern outskirts.

Russian President Vladimir Putin has prioritized capturing the remainder of Donetsk in eastern Ukraine, which contains a fortress belt of heavily fortified cities: Sloviansk, Kramatorsk, Konstiantynivka and Druzhkivka. Ukrainian commander-in-chief Oleksandr Syrskii said assaults on those four cities noticeably increased in April 2026.

Ukrainian officials reported that Russia suffered higher casualties than its rate of recruitment could replenish for the fifth consecutive month. "In April, 35,203 Russian soldiers were eliminated or seriously wounded," Defence Minister Mykhailo Fedorov said. "Russia is gradually drowning in losses," he added. Fedorov said that last year Russia lost about 14,000 soldiers per month to death, with total casualties averaging 34,833 per month.

Ukrainian President Volodymyr Zelenskyy said Ukrainian intelligence had obtained Russian documents reporting that 62 percent of casualties were deaths. Zelenskyy has repeatedly rejected the idea of surrendering Ukrainian territory as part of any peace agreement.

Moscow demanded that Kyiv withdraw its troops from parts of the Donetsk region that forces have failed to capture, but Ukraine refused, insisting it would not cede territory still under its control. The war between Russia and Ukraine has lasted more than four years.