Ukraine will fight to recover all its territory occupied by Russian forces, President Volodymyr Zelensky said on Tuesday, as his troops battled street-to-street in Sievierodonetsk in one of the bloodiest land battles of the war.

“We have already lost too many people to simply cede our territory,” he said by video link at an event hosted by Britain’s Financial Times newspaper.

Stalemate was “not an option”, he said. “We have to achieve a full deoccupation of our entire territory.”

Zelensky’s remarks were a forceful response to suggestions that Ukraine must cede territory to Russia to end the war, now in its fourth month.

French President Emmanuel Macron said in a recent interview that it was important not to “humiliate” Moscow, comments interpreted in Ukraine as implying it must accept some Russian demands.

Asked about Macron’s comments, Zelensky said: “We are not going to humiliate anyone, we are going to respond in kind.”

As he spoke, Ukrainian troops in the ruins of Sievierodonetsk were trying to hold onto gains Kyiv had claimed to have made in a surprise counter-offensive that shifted momentum there last week.

The fight for the small eastern industrial city has emerged as a pivotal battle, with Russia focusing its offensive might in the hope of achieving one of its stated aims — to fully capture surrounding Luhansk province on behalf of separatist proxies.

The situation inside the city could not be independently verified, but Ukrainian officials appear to have backed away from claims to have regained control of as much as half of it. After saying for days that Ukrainian forces had recaptured substantial territory, Luhansk regional governor Serhiy Gaidai said on Monday the situation had again deteriorated.

Other Ukrainian officials spoke of heavy battles underway. Moscow has said its own troops have been advancing.

Britain’s defence ministry said on Tuesday that Russia was still trying to cut off Sievierodonetsk by advancing from the north near Izium and from the south near Popasna. It said Russia’s progress from Popasna had stalled over the last week, while reports of shelling near Izium suggested Moscow was preparing a new offensive there.