Russian forces on Tuesday inched closer to the central part of Vovchansk, a town in Ukraine’s northeast that they have been attacking for the past 10 days as part of a new offensive in the region.
Roman Semenukha, the deputy head of the military administration in the northeastern Kharkiv region, said on television on Monday that Ukrainian forces had lost about 40 percent of the town, with Russian troops pushing from the north.
Open-source maps of the battlefield compiled by independent groups also show that Russia now controls the northern part of the town, which had a prewar population of 17,000.
Vovchansk, which lies just five miles from the Russian border, has been a prime target of Moscow’s new offensive Both U.S. officials and President Vladimir V. Putin of Russia have said the offensive is part of an effort to establish a buffer zone.
The intention, analysts and military officials say, is to push Ukrainian forces away from the border, to prevent them from targeting Russian towns and cities with artillery.
“The Kremlin’s forces will try to make further advances in the weeks ahead, and try to carve out a buffer zone along the Ukrainian border,” Lloyd J. Austin III, the U.S. defense secretary, said on Monday during a meeting with Western allies of Ukraine.
Russian forces have also advanced to the west of Vovchansk, pushing about five miles into Ukrainian territory just north of Kharkiv, Ukraine’s second largest city. They now control more than 70 square miles of Ukrainian land in the area and have made their largest territorial gains since the end of 2022.
Ukrainian officials have said in recent days that the situation in the region has stabilized thanks to the urgent redeployment of Ukrainian units that have managed to slow the Russian advance.
The Ukrainian Army has warned that Russia could open another front further north of Kharkiv, toward the city of Sumy. Officials have said that Russia is concentrating forces across the border and carrying out sabotage and reconnaissance raids in the area.
Gen. Kyrylo Budanov, the head of Ukraine’s military intelligence, told The New York Times last week that he expected Russian forces to make a hard push in the direction of Sumy after the culmination of their offensive in the Kharkiv region.
For now, Russian troops appear determined to capture Vovchansk. They have been pounding the town for days with powerful guided weapons known as glide bombs that can deliver hundreds of kilograms of explosives on impact, Ukrainian officials said.
After reaching the outskirts of the town in the first days of their offensive 10 days ago, Russian forces slowly pushed inside it, engaging in street fighting.
Oleh Syniehubov, the head of the Kharkiv regional military administration, said on Monday that the front line in Vovchansk now runs along the Vovcha river, which separates the northern part of the city from the rest of it. “Our soldiers are trying to take back house by house, street by street,” he said.
Russian forces have also conducted strikes on bridges across a river running further south, in what appears to be an attempt to disrupt Ukraine’s logistical lines in the area.
“Vovchansk is the largest settlement immediately on the border that would provide Russian forces a staging ground close to the Russian rear to prepare for and launch the second phase of the Russian offensive operation,” the Institute for the Study of War, a Washington-based think tank, said over the weekend.
Ukrainian authorities have been scrambling to evacuate under fire residents from the town.
“The situation in Ukraine has once more dramatically deteriorated with the massive Russian airstrikes on the civilian infrastructure and the brutal Russian offensive in the Kharkiv area,” the German foreign minister, Annalena Baerbock, said on Tuesday during a visit to Kyiv.
