Ukrainian President Volodymyr Zelenskyy on Wednesday asked the head of the UN to help save the lives of the remaining wounded Ukrainians trapped underneath the giant Azovstal steel plant in Mariupol.
"The lives of the people who remain there are in danger," Mr Zelenskyy told UN Secretary General Antonio Guterres by phone, after thanking him for a successful evacuation this week.
"Everyone is important to us. We ask for your help in saving them."
He called on the UN to "assist in the removal of all the wounded from Azovstal".
Ukraine said on Wednesday that there were fierce battles with Russian troops at the plant, where Ukrainian soldiers had been holed up with civilians for weeks.
Mr Zelenskyy said this week's evacuations, led by the UN and Red Cross, moved more than 100 people trapped in the Azovstal plant to safety, showing the world "that international organisations can be effective".
He "expressed hope for a successful continuation of the ongoing evacuation operation".
Moscow, which has denied it was storming the plant, said its forces would cease fire there to open a humanitarian corridor for civilians for three days starting on Thursday.
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"The Russian armed forces will, from 8am to 6pm on May 5, 6 and 7, open a humanitarian corridor from the territory of the Azovstal metallurgical plant to evacuate civilians," the defence ministry said on Wednesday.
Civilians sheltering at the plant will be allowed to travel to Russia or Kyiv-controlled territory, the ministry said.
