Ukrainian Commander-in-Chief Major General Mykhailo Drapatyi suggested a headquarters restructuring to support defense in Donetsk Oblast during a meeting with President Volodymyr Zelensky on August 26. President Zelensky announced the creation of two new formations commanded by Brigadier General Andriy Biletsky of the 3rd Army Corps and Brigadier General Denys Prokopenko of the 1st Corps (Azov National Guard). The announcement did not specify force deployment or the structure of the new units. Russian forces continued two main offensives in Donetsk Oblast, targeting the northern and southern sectors of the Fortress Belt. In the southern sector, Russian troops intensified efforts to advance toward Slovyansk from the east and southeast after earlier failures to capture the city from the northeast via Lyman. Russian forces also pressed forward in Kostyantynivka, where Ukrainian units retain a limited presence in the north and northwest while withdrawing from the southeastern part of the settlement to the eastern bank of the Kryvyi Torets River. Observer Kostyantyn Mashovets reported that Russian main-body elements have not entered most of Kostyantynivka, though small infantry groups have infiltrated the area. Russian units have also moved along the Novodmytrivka-Molocharka line toward Stinky, aiming to outflank Ukrainian positions east of Kostyantynivka and west of Chasiv Yar. The Kremlin has claimed that Russian forces seized Kostyantynivka as early as July 5, contrary to evidence that Ukrainian forces remain in the city. ISW assesses that continued Russian infiltrations in and around Kostyantynivka are unlikely to produce a rapid breakthrough against the Fortress Belt or all of Donetsk Oblast. Russian forces have intensified a battlefield air interdiction campaign against Slovyansk, using Smerch and Tornado-S multiple launch rocket systems, glide bombs, and strike drones to degrade logistics and set conditions for a ground offensive. Military Administration Head Vadym Lyakh reported on August 26 that Russian strikes on August 26 damaged at least 13 residential buildings and that five FAB-500 glide bombs hit Raihorodok the previous day. ISW notes that glide bomb attacks have enabled infantry advances near Kostyantynivka by creating rubble for cover. In the northern sector, Russian forces have conducted infiltration missions in Sumy Oblast, while Ukrainian units reported strikes on Russian personnel in western Kindrativka and south of Andriivka. The Russian Ministry of Defense claimed the seizure of Pysarivka, a claim disputed by Ukrainian sources and ISW, which says some footage supporting the claim may have been altered. Eastern Ukraine operations included limited advances by Ukrainian forces in the Kupyansk direction and near Dvorichna. Milbloggers reported Ukrainian counterattacks near Katerynivka, Nove, and Ridkodub, and assessed that Russian forces are losing control of the Shandryholove salient. Russian units continued to use dense vegetation and improvised shelters to complicate identification by Ukrainian drone operators. In the Donetsk sector, Ukrainian forces struck Russian positions in eastern Dibrova and north of Rai-Oleksandrivka following reported Russian infiltrations. Ukrainian units also advanced in the Dobropillya area, with geolocated footage showing movements in Vodyanske and Krasnopodillya. Russian milbloggers claimed the seizure of Zolotyi Kolodyaz and advances near Novovodyane and Bilozetske, claims ISW has not independently verified. In western Zaporizhia, false reporting by Russian commanders impeded offensive operations, according to a milblogger and a leaked MoD map from April 2026. Ukrainian officials ordered the evacuation of children and parents from nine frontline settlements near Zaporizhzhia City on August 26. Ukrainian long-range strike operations targeted Russian oil and logistics infrastructure, including the Lukoil-Nizhegorodnefteorgsintez refinery in Kstovo, a Wildberries logistics center in Kotovsk, and several air-defense and radar sites in Rostov Oblast and Krasnodar Krai. On the night of August 25-26, Russian forces launched 162 drones from Kursk, Oryol, Krasnodar Krai, occupied Donetsk, and Crimea. Ukrainian air defenses downed 134 drones and reported damage at 19 locations. Belarus is expanding its military infrastructure near the Ukrainian border, constructing a new railway line to a training ground in Gomel Oblast that will support the deployment of the 37th Separate Airborne Assault Brigade. Overall, the assessment indicates that Russian offensive efforts remain focused on incremental gains in Donetsk Oblast, while Ukrainian forces continue to conduct localized counter-attacks and long-range strikes against Russian supply lines and infrastructure.