Ukraine’s President Volodymyr Zelensky said “influential mediators” are involved in talks to rescue soldiers trapped in the Azovstal plant in Mariupol.
Around 2,000 fighters remain holed up in tunnels and bunkers underneath the plant amid claims that Russians have continued a ground assault on the complex in recent days.
“We are also working on diplomatic options to save our troops who are still at Azovstal,” he said in his nightly video address.
Mr Zelensky said “influential states” are involved in efforts to rescue the soldiers, although he did not mention any by name.
It comes after dozens more civilians were rescued from the tunnels under the steel mill on Friday.
Russian and Ukrainian officials said 50 people were evacuated and handed over to representatives of the United Nations and the International Committee of the Red Cross, while it is estimated 100 civilians still remain in the plant.
UN officials have been tight-lipped about the civilian evacuation efforts, but it seemed likely that the latest evacuees would be taken to Zaporizhzhia, a Ukrainian-controlled city about 140 miles (230 kilometers) northwest of Mariupol where others who escaped the port city were brought.
Fighters defending the plant said Friday on the Telegram messaging app that Russian troops had fired on an evacuation vehicle on the plant’s grounds.
They said the car was moving toward civilians when it was hit by shelling, and that one soldier was killed and six were wounded, although Russia has denied the accusation.
Russia took control of the rest of Mariupol after bombarding it for two months. Ahead of Victory Day, municipal workers and volunteers cleaned up what remains of the city, which had a prewar population of more than 400,000.
The fall of Mariupol would deprive Ukraine of a vital port. It would also allow Russia to establish a land corridor to the Crimean Peninsula, which it seized from Ukraine in 2014, and free some Russian troops to fight elsewhere in the Donbas, the eastern industrial region that the Kremlin says is now its chief objective.