The Ukrainian troops face “difficult” defense operations in parts of the eastern front as the bitter cold of winter prevails, but forces in the south are still carrying out attacks, said Wednesday Ukrainian President Volodymyr Zelensky.

Russian troops have launched attacks in various sectors of the front line in eastern Ukraine this fall, trying to advance on the devastated city of Avdiyivka and the northeastern section between the cities of Liman and Kupyansk.

“Difficult weather, difficult defense on the fronts of Liman, Bahamut, of Donetsk and Avdiivka. Aggressive actions in the south,” Zelensky said on the Telegram messaging app.

Snow and freezing temperatures reaching minus five degrees Celsius during the day and expected to drop even lower may further hamper operations on the battlefield as the fighting moves into a waning phase.

Russia, which launched a full-scale invasion in February 2022, controls about a fifth of Ukraine. Kiev launched a counteroffensive in the summer to recapture the occupied territories, but has not made much progress.

From mid-October, Avdiivka, where the front line it has changed little since the first war broke out in 2014 between Kiev and Russian-backed militants, faced waves of attacks followed by a temporary lull, according to the Ukrainian military.

After a break a day earlier, the head of the military command “Tavria” said today that Russian troops have “dramatically increased” the number of attacks and airstrikes.

“Our defending soldiers are firmly holding the defense in the direction of Avdiivka,” commander Oleksandr Tarnavskyi said in a Telegram post, adding that Ukrainian forces were continuing their offensive on Melitopol’s southeastern front.

In its morning report on the battlefield, the General Staff reported that troops also hold the bridgeheads which they had secured on the eastern side of the Dnipro River, which had been occupied by Russian forces in the first days of their invasion.

Reuters was unable to independently verify reports of what was happening on the front lines.