Russian troops have breached Ukrainian defensive lines in the eastern Donetsk region, advancing roughly 10 kilometres in several areas north-east of Pokrovsk over the past few days, according to President Volodymyr Zelensky, Ukraine’s General Staff and military monitoring group DeepState_UA. The push, achieved largely by small infantry units operating without heavy armour, marks the fastest Russian territorial gain in months and the largest Ukrainian setback reported in more than a year. The incursion threatens to cut the Dobropillia–Kramatorsk highway, a vital supply route for Kyiv’s forces defending the industrial cities of Kramatorsk and Sloviansk. Analysts at the Institute for the Study of War described the situation as “complex and dynamic”, adding that it is too early to declare an operational breakthrough but warning that the coming days will be critical if Moscow seeks to consolidate the narrow corridor it has opened. Ukraine’s General Staff said it is deploying reinforcements and implementing “effective measures” to halt the advance, while Zelensky insisted that steps are being taken to “correct the situation”. Lieutenant-Colonel Bohdan Krotevych, a National Guard officer formerly with the Azov Brigade, characterised conditions along the Pokrovsk–Kostiantynivka line as “chaos” and urged clearer leadership from Kyiv. The Russian momentum comes ahead of a 15 August summit in Alaska between U.S. President Donald Trump and Russian President Vladimir Putin, heightening concern in Kyiv that battlefield losses could weaken its negotiating position. Zelensky has previously acknowledged manpower shortages at the front, complicating efforts to stabilise the line.