Ukraine’s leaders now face a key strategic decision: withdraw from the mid-sized city and take up more defensible positions, or stay and risk being locked down if the bridge explodes. It reflects the choices the country has had to make since the start of the Russian invasion, between giving ground to avoid near-term death and destruction, and resisting long chances in the hope that it will pay off more. late.

In Sievierodonetsk, this calculation took on significance beyond the limited military importance of the city. In remarks to reporters on Monday, President Volodymyr Zelensky called Sievierodonetsk and its neighbor across the river Lysychansk “ghost towns” ravaged by Russian attacks and nearly empty of civilians.

And yet he insisted there was a compelling reason to stay and fight: Ukraine’s position throughout the war has been that it intends to retain its sovereign territory and not to cede it to Moscow.

Withdrawing now to better positions on higher ground across the Seversky Donets River and then fighting to retake the town later, he said, would be more difficult and incur a higher price in bloodshed than to hold on.

“It will be very costly for you to come back, in terms of the number of people killed, the number of casualties,” Mr Zelensky said.

“Our heroes are not abandoning their positions in Sievierodonetsk,” he added. “Fierce urban fighting continues in the city.”

It was a rare public rumination by Mr. Zelensky on strategic decision-making during the war, providing a window into the goals of his government and military. Sievierodonetsk is the last major city in the separatist region of Luhansk that the Russians did not take; capturing it would give them near total control of this enclave.

There are also other factors. Withdrawing could be demoralizing for Ukrainian forces. And some Ukrainian soldiers said it was worth extending the urban combat phase to inflict more casualties on the already depleted Russian forces, and possibly hurt their morale.

It was also possible that Mr. Zelensky had helped the military mislead by signaling an intent while quietly pursuing an opposing course of action.

The government has not specified the total number of military casualties Ukraine has suffered since Russian leader Vladimir V. Putin ordered the invasion in February. But Mr Zelensky said last week that in recent heavy fighting, his country was losing between 60 and 100 soldiers killed and 500 wounded every day. Russian Defense Minister Sergei Shoigu said on Tuesday that 6,489 Ukrainian servicemen had been captured.

Ukraine’s Interior Ministry this week put the number of civilian casualties at 40,000 killed or injured, although some government officials say the actual figures are higher. Ukrainian officials said on Tuesday that ruptured sewage and water pipes in the southern city of Mariupol, seized by Russia after a devastating siege, created the risk of serious disease outbreaks that would increase the civilian toll.

The battle for Sievierodonetsk, which is part of Lugansk and the wider Donbass region to the east, has been raging for weeks, and some Ukrainian soldiers are wondering why the army has not ordered a tactical retreat.

“They kill a lot of our guys,” said a soldier who asked to be identified only by his nickname, Kubik, when interviewed last week while smoking by the side of a road in the town of Siversk, an area of rally west of the fighting. He had recently moved away from his positions near Sievierodonetsk.

“Let them come forward a bit, let them think they’ve captured the city, and then we’ll meet them beautifully” from the most advantageous position, he said.

The city lies on the mostly flat eastern shore of the Seversky Donets. The west bank, on the other hand, rises on a prominent hill that offers commanding views and firing positions.

Earlier in the war, Ukrainian soldiers were surrounded in Mariupol and fought for weeks, eventually retreating to retain only a small pocket of ground at a steelworks complex where they sheltered in bunkers , before Mr. Zelensky ordered the resisters to surrender rather than be killed. .

Ukrainian commanders decided to avoid a smaller-scale version of that siege earlier this week in Sviatohirsk, a town on the lower bank of the Seversky Donets.

Trying to trap Ukrainian troops in the town, Russian forces had fired artillery at their only remaining route across the river, a bridge near an Orthodox monastery which was also frequently hit. On Monday, the Ukrainian army withdrew, blew up the bridge and took up position on the upper bank of the river, Ukrainian officials said.

Sievierodonetsk was once a sleepy provincial backwater of around 100,000 people, with poplar-lined streets and a skyline dominated by the chimneys of a fertilizer factory.

Today it is a largely abandoned ruin where the battle lines often sway, with each side sometimes claiming to have expelled the other from part of the city. On Tuesday, Serhiy Haidai, Ukraine’s military governor of the Luhansk region, said Russian forces were again storming positions. “The fight continues,” he said.

Russian artillery fire into the potential fallback position on the high bank, where Lysychansk is located, was also fierce. The shelling hit a market, a mining academy and a school, Haidai said. The market strike sparked a fire that burned all day Monday. Two civilians were injured.

The Ukrainian government has underlined the precariousness of its positions in the battle for Donbass, the mining and agricultural region now mainly controlled by Russian forces.

The pivotal access bridge to Sievierodonetsk is a panorama of destruction, testifying to the difficulty and risk for Ukraine to hold even a part of the city.

Video recorded by Radio Free Europe/Radio Liberty journalists who took part in a resupply run last week showed the chaos on the span: crossing it meant weaving between the burnt carcasses of cars and shell craters in the bridge deck.

Debris has accumulated over the past two weeks. In an interview in late May, a soldier at a sandbag checkpoint at the western end of the bridge warned that Russian artillery observers had the range – free of debris at the time – under observation and were opening the fire whenever a car passed. Two other bridges in the city were destroyed earlier in May.

Mr. Haidai justified Ukraine’s efforts to hold Sievierodonetsk in part as a matter of symbolic resistance.

“Strategically, the city of Sievierodonetsk is not of great importance,” he said over the weekend. The opposite high bank is militarily more important, he said. “But politically, Sievierodonetsk is a regional center. His release will greatly boost our morale and demoralize the Russians.

Still, Mr Zelensky said he was ready to reconsider his decision based on developments. Either command – hold ground or retreat – had potential downsides, he said.

“In the first option there is a risk, in the second there is a risk,” he said.

Oleksandr Chubko contributed report.