Mariupol has not surrendered to the Russians, Ukrainian Prime Minister Denys Shmyhal said Sunday.

He spoke on ABC News’ “This Week” hours after a Russian-set deadline for surrender in the besieged city. Shmyhal said only Kherson had fallen to Russian control. 

The Russian military said it would spare the lives of Ukrainian troops in the besieged city of Mariupol if they surrendered by 6 a.m. Moscow time on Sunday. Describing the conditions there as “hopeless,” the defense ministry offered the cease-fire “out of purely humane principles,” the Russian news agency Tass reported.

“All those who will continue resistance will be destroyed,” Maj. Gen. Igor Konashenkov, the Russian Defense Ministry’s spokesman, said. He said intercepted communications indicated there were about 400 foreign mercenaries along with the Ukrainian troops at the Azovstal steel mill, a claim that couldn’t be independently verified.

Ukrainian President Volodymyr Zelenskyy said Saturday the situation in Mariupol is “inhuman,” after six weeks of holding out against relentless Russian forces. 

Ukrainians defending the port city are facing a shortage of weapons and supplies, and the situation for civilians still remaining has long since become dire. Zelenskyy said Russia “is deliberately trying to destroy everyone who is there,” and said the fate of the city will be key in whether negotiations can end the fighting.

Zelenskyy said he spoke with leaders of Britain and Sweden on Saturday to discuss how to help forces defending Mariupol.

“Either our partners give Ukraine all of the necessary heavy weapons, the planes, and without exaggeration immediately, so we can reduce the pressure of the occupiers on Mariupol and break the blockade,” he said in his nightly video address to the nation. “Or we do so through negotiations, in which the role of our partners should be decisive.”