Russia has launched 574 drones and 40 missiles on Ukraine in one of the heaviest bombardments in weeks, Ukrainian officials say.
One person was killed in a drone and missile strike on the western city of Lviv, while 15 others were reported wounded in an attack on the south-western Transcarpathia region.
The attacks came as US President Donald Trump spearheads diplomatic moves to halt the war. Ukrainian Foreign Minister Andrii Sybiha said the strikes highlighted why efforts to bring it to an end were "so critical".
President Volodymyr Zelensky has said Ukraine was ready to meet Russia's Vladimir Putin "in neutral Europe" - mooting Switzerland or Austria - adding that he was not against Istanbul either.
Zelensky has stated his willingness to meet Putin in "any format", although he has poured cold water on the idea of talks taking place in Budapest, which he said "is not easy today".