The Russian-installed head of the Kupiansk city administration, Vitaly Ganchev, urged women and children to evacuate the city as Ukrainian forces approached.
Ganchev said the city, which lies west of the Donbas region and about 70 miles east of the city of Kharkiv, “is constantly under terror” and experiencing “constant rocket attacks from the Armed Forces of Ukraine.”
While the southern front looks set to be one of the main theaters of conflict as the war heads towards winter, a new Ukrainian push in Kharkiv could stretch Russian forces across two disparate locations.
Kyiv “likely used tactical surprise to advance at least 20km into Russian-held territory in eastern Kharkiv Oblast on September 7, recapturing approximately 400 square kilometers of ground,” the Institute for the Study of War (ISW), a Washington-based analytical group, said its daily report on the conflict on Wednesday.
“Ukrainian forces likely took prudent advantage of a reallocation of Russian troops, equipment, and overall operational focus to launch localized counteroffensives toward critical points in Kharkiv Oblast,” the ISW said.
In recent weeks, Russia redeployed some forces to the south to bolster its ranks ahead of the Ukrainian counteroffensive in Kherson region, according to Ukrainian officials and footage of equipment moving through Crimea geolocated by CNN.
Russian military bloggers and analysts have reported Ukrainian forces’ push towards Kupiansk aims to cut off supply lines to the strategic city of Izium to the south.
Zelensky was coy on whether specific settlements have been retaken by Ukrainian forces in his nightly address on Wednesday. But the President thanked three brigades involved in operations to recapture Russian-held territory there.
“This week we have good news from Kharkiv region,” Zelensky said. “Probably, you all have already seen reports about the activity of Ukrainian defenders. And, I think, every citizen feels proud of our soldiers. It is a well-deserved pride.”
He also thanked units stationed in southern Ukraine what he called “extremely successful hits” on occupying Russian forces, while the simultaneous counter-attack was launched in the north.
“The more difficult it is for the occupiers, the more losses they have, the better the positions for our defenders in Donbas will be, the more reliable the defense of Zaporizhzhia, Mykolaiv, and the cities of Dnipropetrovsk region will be, the faster we will be able to liberate the Azov region and the entire south,” he said.
The last week has seen the most ambitious ground assaults by the Ukrainians since the beginning of the invasion, following sustained attacks on command posts, ammunition stores, and fuel reserves far behind the front lines, according to geolocation of video and satellite imagery.
The US has observed Ukrainian forces achieve some success in attacking Russian supply lines, with the intention of cutting off and isolating Russian troops currently deployed west of the Dnipro River, according to a senior US official.
CNN’s Yulia Kesaieva, Mick Krever, Jim Sciutto and Tim Lister contributed reporting