KYIV, Ukraine — Less than a month after driving Russian forces from the city of Kherson on the west bank of the Dnipro River, the Ukrainian authorities on Saturday issued an urgent call for civilians to evacuate from Russian-occupied areas on the eastern bank, suggesting that Kyiv’s military might press its offensive and try to establish a foothold across the waterway.
“The evacuation is necessary due to the possible intensification of hostilities in this area,” Yaroslav Yanushevych, the head of the Kherson regional military administration, in Ukraine’s south, said in an announcement to residents.
It was not clear how many people would be able to make it across the river on private boats and other vessels because all of the main crossings have been destroyed. The public call for evacuations was also most likely intended to signal to the Russians that an assault might be coming, though Ukraine has in the past used deception to focus Russian attention in one direction while preparing for an offensive somewhere else.
Ukrainian forces are pushing on into the winter after two sweeping offensives in the northeast and south in the fall. They are once again stepping up strikes on Russian supply routes, command centers and ammunition depots from new forward positions.
The Russian withdrawal from Kherson was both an embarrassment for the Kremlin, which had only recently declared the region to be a part of Russia, and a strategic setback as it put the Ukrainians in a better position to threaten supply lines from Crimea with long-range precision weapons provided by its Western allies.
After being driven across the Dnipro River in Kherson, Russian forces set about fortifying defensive positions about 10 to 20 miles from the eastern bank, according to the Ukrainian military and satellite imagery. But the river divides Ukrainian and Russian forces along a route that stretches more than 200 miles, and Russian forces are spread thin.
“Russian forces clearly do not expect to be able to prevent Ukrainian forces from getting across the river, nor are the Russians prioritizing defensive positions to stop such a crossing,” the Institute for the Study of War, a Washington-based research group, said earlier this week after analyzing publicly available satellite photos of the Russian defensive positions.
A ban on river crossings would be lifted from Saturday to Monday to facilitate the evacuations, Mr. Yanushevych said, noting that only one dock would be opened. All those fleeing Russian-occupied territories must bring documents certifying their identity and confirming their Ukrainian citizenship, he said.
Farther to the northeast, where the river widens into a vast reservoir held back by vital dam in Nova Kakhovka, Ukrainian officials and residents said that the Russian civilian administration this week had begun to flee farther east.
The Ukrainian military has noted that it was seeing a decrease in the number of Russian troops in the towns and villages along the river. “A minimal number of occupiers remain in the cities,” the military said last month.
The account was supported by local residents reached by telephone in recent days.
North of the dam, speculation continued to swirl around Russian intentions at the Zaporizhzhia Nuclear Power Plant, which has been occupied by Russian forces since early in the war and where Ukrainian intelligence has estimated at least 500 soldiers are garrisoned.
Rafael Mariano Grossi, the head of the International Atomic Energy Agency, said at a news conference in Rome on Friday that the agency was “almost there” in brokering a deal for Russian troops to pull out of the plant and to create a demilitarized zone around the facility, which has been at the center of frequent shelling.
“We have a proposal on the table which simply put is aiming to stop the folly of bombing the largest nuclear power plant in Europe,” he said.
Although the Kremlin has pushed back on Ukrainian suggestions that its forces were preparing to leave the nuclear plant, Alexei Likhachev, the head of the Russian nuclear energy agency confirmed negotiations with the International Atomic Energy Agency, the United Nations’ nuclear watchdog group, were continuing.