Ukrainian President Volodymyr Zelenskyy vowed he would not back down in the fight to regain territory lost to Russia after the top US general warned it was unclear how Moscow would respond to its battlefield setbacks in Ukraine.
Britain said Russian forces had escalated attacks on civilian infrastructure following battlefield setbacks and were likely to expand their targets further.
Ukraine’s military said on Sunday that its forces repelled attacks by Russian troops in the areas of Kharkiv region to the east and Kherson to the south, where Ukraine launched counter-offensives this month, as well as parts of Donetsk in the south-east.
It was said that Ukrainian troops had advanced to the east bank of the Oskil River in the Kharkiv region.
“Since yesterday, Ukraine has controlled the east bank,” it said on Telegram. Serhiy Gaidai, governor of the neighboring Luhansk region, said this means that the “disoccupation” of his region is “not far away”.
In his nightly address on Sunday, Zelenskyy vowed to keep up the pressure on Moscow.
“Perhaps it seems to some of you that after a string of victories, we’re now on a bit of a hiatus,” he said in his regular nightly address. “But there will be no pause. There are preparations for the next series… Because Ukraine must be free. All of that.”
Ukrainians returning earlier this month to the northeastern area retaken by Kiev’s lightning advance searched for their dead while Russian artillery and airstrikes continued to bombard targets in eastern Ukraine.
On Friday, Russian President Vladimir Putin brushed aside Ukraine’s rapid counteroffensive, saying Moscow will respond more forcefully if its troops continue to be pressured.
Such repeated threats have raised concerns that Putin may eventually turn to small nuclear weapons or chemical warfare.
When asked what he would say to Putin if he considered using such weapons, US President Joe Biden replied in an interview with CBS’ 60 Minutes: “No. Not. Not. It would change the face of war like nothing since World War II.”
Some military analysts have said Russia could also stage a nuclear incident at Zaporizhzhia, Europe’s largest nuclear power plant, which is held by Russia but operated by Ukrainian personnel.
Moscow and Kyiv have accused each other of shelling the plant, which damaged buildings and cut power lines needed to keep it cool and safe.
US Army Gen. Mark Milley, chairman of the Joint Chiefs of Staff, called for vigilance Sunday after visiting a base in Poland supporting Ukraine’s war effort.
“The war is not going so well for Russia right now, so it is our duty to maintain a high level of preparedness and alert,” he said.
In an intelligence update, Britain’s MoD said Russian attacks on civilian infrastructure, including a power grid and a dam, had intensified.
“Faced with setbacks at the front lines, Russia likely expanded the targets of its attacks to try to directly undermine the morale of the Ukrainian people and government,” it said.
On Saturday, Zelenskiy said authorities had found a mass grave in Izium containing the bodies of 17 soldiers, some of whom showed signs of torture.
Ukrainian officials said last week they found 440 bodies in forests near Izium. They said most of the dead were civilians and the causes of death had not been determined.
The Kremlin has not commented on the discovery of the tombs.