Ukraine says Russian shelling is still preventing the evacuation of civilians from besieged cities.
Attacks are said to continue despite a proposal from Russia to create safe escape routes.
Russia said humanitarian corridors would allow people to leave Kyiv, Mariupol, Sumy and Kharkiv today.
However, Ukraine branded the proposal “immoral” after it emerged many of the routes would only take civilians to Russia or its ally Belarus.
Two ceasefire attempts in Mariupol, where people are running out of food, collapsed at the weekend.
About two thousand people have been able to flee Irpin, north-west of the capital Kyiv, despite continued Russian shelling.
Oil prices have soared to a 13-year high due to the crisis.