British Defence Intelligence Update Ukraine July 10, 2026

On 03 July 2026, Russian Chief of the General Staff Gerasimov briefed President Putin that Russian forces had fully captured Kostiantynivka, a key urban centre in Donetsk oblast within the Ukrainian fortress belt. Russia had first attempted to seize the city in summer 2025. It is highly unlikely that Russia has fully secured Kostiantynivka. Instead, it is assessed that Russia likely occupies approximately over half of the urban centre. Open source reporting has identified incidents of Russian flag raising along the northern boundary of the city, but these are highly likely small infiltration groups rather than a consolidated force. This tactic has been used previously in urban centres such as Kupiansk and Siversk as part of Russia’s information operations campaign. It is highly likely that