A Ukrainian counteroffensive could drive Russian forces back from Kharkiv, Ukraine’s second-largest city, according to Mason Clark and George Barros of the Institute for the Study of War.

“The Ukrainian counteroffensive north and east of Kharkiv city secured further gains in the last 24 hours and may successfully push Russian forces out of artillery range of Kharkiv in the coming days,” the U.S.-based think tank said Friday, adding that the Ukrainian operation “is developing into a successful, broader counteroffensive — as opposed to the more localized counterattacks that Ukrainian forces have conducted throughout the war.”

Kharkiv, located in northeastern Ukraine, has been under constant threat since the war began, CNBC explains. The New York Times reported Friday that “Russian front lines north of Kharkiv were stagnant for more than a month” but that “over the last several days, Ukrainian forces have advanced outward from the city.” The Ukrainian infantry assault is supported by artillery, tanks, and other armored vehicles.