The Mayor of the Ukrainian city of Mariupol has told CNN that "one clear day of cease fire" is needed to evacuate civilians sheltering in the Azovstal iron and steel plant.
Hundreds of soldiers and civilians are believed to be hunkered down in the huge industrial complex that has become the final bastion of Ukrainian defenders in the city.
On Thursday, Russian President Vladimir Putin proclaimed the "liberation" of Mariupol by Russian forces, but ordered troops to blockade the steel plant rather than storm it.
Ukrainian officials have denied that the city has fallen to Russia.
"The day before yesterday, we planned to open up an evacuation route that these people [inside the plant] could join," Mariupol mayor Vadym Boichenko told CNN New Day on Friday.
"However, the Russian forces continued bombarding the plant and shelling the plant and we weren't able to get the people out of there."
Yuriy Ryzhenkov, the CEO of Metinvest Holding which owns the Azovstal plant, recently told CNN that the situation inside is "close to catastrophe" as food and water supplies dwindle.
Boichenko added that around 20,000 civilians are estimated to have been killed in Mariupol, which has been leveled by Russian attacks during the course of the war.
CNN cannot independently verify the death toll following weeks of heavy bombardment of Mariupol. Evidence has emerged of mass graves outside the city following the publication of satellite images collected and analyzed by Maxar Technologies.
Journalists in the city have also documented the hasty burial of civilians there, and images have surfaced on social media showing bodies apparently left for collection in the city.
Boichenko said that 90% of the city's buildings were destroyed as of March 21.
"It is very painful for me to see this, very painful and sad," Boichenko said.
For eight year, we were trying to develop Mariupol as a showcase for Ukrainian Donbas, for a restored Donbas since the 2014 attempts [by Russia] to take it.
"And it was blossoming. It was turning into a modern city. We were developing it as a modern, state-of-the-art city to fulfil people's dreams as we imagined ... I feel as if my heart has been torn out," he said.