September 21, 2025
Russian forces continue their offensive near Kupyansk and are stepping up efforts on the Pokrovsk front, while Ukrainian troops have recently advanced in northern parts of Sumy Oblast, the Institute for the Study of War (ISW) said in a new report.
Geolocated footage published on Sept. 20 shows that Ukrainian troops recently moved northeast of Kyndrativka, north of the city of Sumy, ISW said.
One Russian military blogger tied to the Kremlin’s Northern Grouping claimed that North Korean troops near the border area of Gornal-Guyevo in Russia’s Kursk Oblast shut down a section of the frontier without informing Russian forces and later fired on their vehicles. The same blogger also claimed that soldiers with Russia’s 30th Motorized Rifle Regiment in Oleksiivka complained of poor operational planning and vague orders from their commanders.
Photo: ISW
Meanwhile, Russian forces made some territorial gains in the north of Kharkiv Oblast. A Ukrainian brigade member operating in the area said Russian troops were now actively using strike drones, including fiber-optic-guided models, to hit Ukrainian communication lines. He added that drone warfare had changed significantly over the past year and now complicated troop rotations.
According to the same source, Chinese, Belarusian and Kenyan fighters have been spotted among Russian forces operating in the area.
Photo: ISW
On Sept. 20, Russian troops attempted to advance near Velykyi Burluk and on the Kupyansk axis but failed to make any confirmed gains, ISW analysts reported.
Photo: ISW
Lt. Col. Oleksii Bielskii, spokesperson for Ukraine’s Dnipro Grouping of Forces, dismissed Russian claims of capturing central Kupyansk as false. He said Ukrainian drones were actively disrupting Russian attempts to move heavy equipment across the Oskil River east of the city.
Russia’s army continued assault operations near Borove and Siversk, and in the areas around Kostyantynivka, Druzhkivka and Dobropillia, but failed to advance.
On the Pokrovsk front, both sides have made some incremental gains recently. An officer with a Ukrainian battalion operating there said on Sept. 20 that Russian troops were only using armored vehicles to shuttle infantry between positions, not to assault fortified Ukrainian lines.
He said Russian forces are heavily shelling Ukrainian positions and are well-equipped, using thermal camouflage cloaks to support their advances. He also noted that Russian commanders have begun deploying two poorly equipped units as decoys to divert attention from a better-armed unit attempting to break through in another direction.
Photo: ISW
In western Zaporizhzhya Oblast, Russian troops have not made progress.
However, Russia continues attacks on the Kherson front, particularly near the Antonivsky railway and road bridges east of the city of Kherson.
Photo: ISW
Col. Vladyslav Voloshyn, spokesperson for Ukraine’s southern defense forces, said on Sept. 20 that Russian forces are concentrating their attacks on those bridges because they span the narrowest section of the Dnipro River. According to him, Russian forces are trying to secure positions near the bridges to be able to launch drones from there.
Voloshyn added that enemy forces regularly attempt to land troops on islands in the Dnipro delta.
On Sept. 19, President Volodymyr Zelenskyy said Ukraine’s Defense Forces were continuing counteroffensive operations in Donetsk Oblast, particularly near Pokrovsk and Dobropillia.