Russia claims capture of key Donbas fortress Kostiantynivka, Ukraine calls it 'another false claim'

The Russian claim

On Friday, President Vladimir Putin heard a report from Chief of General Staff Valery Gerasimov that Russian forces had completely captured Kostiantynivka in Donetsk Oblast. Russian state media reported the city's "liberation", and Putin thanked the soldiers.

Thank you for their heroism and successful work.

The Kremlin also announced full control of Luhansk Oblast and said the offensive in Donetsk Oblast would continue. During the meeting, Putin and Gerasimov discussed creating a "security zone" in Kharkiv and Sumy oblasts and plans for a more active summer offensive.

The more the Armed Forces of Ukraine attack Russian infrastructure, the larger the security zone Russia will have to create.

Russian military sources claimed Ukrainian troops withdrew from the city with significant losses. The General Staff said the "Center" group entered Dobropillia and Annivka, while the "Dnieper" group is 9 km from Zaporizhzhia, and forces are expanding the security belt in Sumy and Kharkiv oblasts.

Ukraine's response

Initially, Ukraine did not comment, but on Saturday the General Staff of the Armed Forces of Ukraine rejected the claims.

We deny this. These are another false claims.

The city is part of the so-called fortress belt in Donbas, which also includes Druzhkivka, Sloviansk, and Kramatorsk, and remains under Ukrainian control according to Kyiv.

ISW assessment

The Institute for the Study of War (ISW) had already warned that Putin makes exaggerated claims. Last week, ISW experts stated that Putin "continues to make heavily exaggerated claims about Russian progress that do not correspond to battlefield realities, in order to build a narrative of ubiquitous Russian military success." They cited his claims about Lyman, Mykolaivka, and Kramatorsk. According to ISW, Russian forces hold only 4.3% of Lyman, are about 12 km from Mykolaivka and 14 km from Kramatorsk, not the distances Putin asserted. For Kostiantynivka, Putin claimed 96% control, but ISW assessed Russian presence at just 36.96% of the city, with no established control.

Strategic importance

Kostiantynivka lies about 55 km north of Donetsk and is a key railway hub, crucial for supplying Ukrainian forces in the Kramatorsk and Sloviansk areas. Intense fighting for the city began in October 2025. Its capture would open a path toward the remaining Ukrainian-held strongholds in Donetsk Oblast.

Broader context

On 26 June, President Volodymyr Zelensky announced a 40-day "super operation" of pressure on Russia through medium- and long-range drone strikes, aiming to force an end to the war. On the first day, Ukraine sent 660 drones. Colonel Piotr Lewandowski, a lecturer at the Territorial Defense Forces Training Center, commented that the announcement was linked to the imminent Russian claim of capturing Kostiantynivka, which he expected to be true. He also predicted the fall of Lyman, noting that this is the tenth Donbas campaign, the weakest in about 2.5 years, and that Russia is fighting with volunteers without mobilization, so its capabilities are slowly ending.