Ukraine said it aimed to establish up to 10 humanitarian corridors to evacuate trapped civilians on Friday, but civilians trying to flee besieged Mariupol will have to use private vehicles.
The 10 planned safe corridors announced by Deputy Prime Minister Iryna Vereshchuk were all in southern and eastern Ukraine.
Ukrainian officials say Russian forces have been regrouping for a new offensive, and that Moscow plans to seize as much territory as it can in the eastern part of Ukraine known as Donbas bordering Russia.
Vereshchuk said 4,676 civilians had been evacuated from Ukrainian towns and cities on Thursday.
Multiple attempts to agree safe passage for buses to take supplies to Mariupol and bring out civilians have failed since Russia invaded Ukraine on Feb. 24, with each side blaming the other.
Mayor Vadym Boychenko put the civilian death toll in the port city on the Sea of Azov at about 5,000 over a week ago, and tens of thousands are still trapped without power and with few supplies.
