Russian troops are trying to drag Radkivka, a village on the northern edge of Kupiansk in Kharkiv Oblast, into the gray zone so their infiltration groups can keep reaching the city, Viktor Trehubov, spokesperson for Ukraine’s Joint Forces Grouping, said on national television on 27 October, Ukrinform reported. Russian forces made three attempts to advance toward Radkivka on 26 October, Ukraine’s General Staff reported.
Russia has tried for more than a year to retake Kupiansk, a city on the Oskil River, largely by slipping small groups through a disused gas pipeline under the river. They kept using it even after Ukraine said in September 2025 that it had flooded three of the four pipe strings, until Ukrainian troops went into the pipes themselves in Operation Veles, announced on 22 October.
Russian groups now have to move above ground
The pipe Russian groups used to seep toward Kupiansk has been put out of action, so they now have to go through Radkivka or neighboring Holubivka, Trehubov said. They move along the bank of the Oskil and a nearby tree line, but the foliage will soon be gone, which will make that much harder.
When the battlefield became transparent, the war went underground.
— Khartiia Corps in English (@khartiia_eng) October 21, 2026
Khartiia Corps, together with other Defense Forces units, is conducting the underground Operation VELES, and for the first time, we can show the work of our brothers-in-arms in this new dimension of warfare.
“We… pic.twitter.com/Af3RqgSIr8
On the western bank of the Oskil, Russian forces took losses from Ukraine’s Khartiia Corps and in Operation Veles, and their logistics have “suffered noticeably,” Trehubov said. Advancing there is now harder for them than it was a month ago, he added.
Everything now depends on how the fights for Holubivka and Radkivka end, Trehubov said.
“If Ukrainian control can finally be established there, the Russians will have nowhere much to crawl through,” he said.
Several dozen Russian soldiers remain in low-rise buildings in northern Kupiansk, and Ukrainian forces are working to cut off their rotations, Trehubov said on 23 October.
Each side wants the other off its bank of the Oskil
On the eastern bank, Russian forces keep pushing toward the village of Podoly and Kupiansk-Vuzlovyi, a railway junction town southeast of Kupiansk, aiming to wipe out Ukraine’s foothold there, Trehubov said. Ukraine wants to destroy the Russian foothold on the western bank.
“For that, we will need to at least somehow throw them out of Dvorichna,” Trehubov said, referring to a town north of Kupiansk.
The US-based Institute for the Study of War (ISW) assessed that Russian forces conducted no offensive operations on the Kupiansk axis on 26 October, likely because Ukraine now controls the pipeline, a view at odds with the General Staff’s report for that day.
Ukraine reported confident control of Kupiansk as early as February, yet Russian groups kept slipping into the city for months afterward. Trehubov’s latest assessment stops short of declaring that threat over: Russia will still try to advance, he said.