A Russian attack on the central Ukrainian city of Poltava on Tuesday left 51 people dead and more than 200 injured. It was one of the deadliest attacks of the war.
Two ballistic missiles hit an educational facility and a hospital, trapping people in the rubble.
Russia also attacked the eastern region of Kharkiv and the capital Kyiv on Monday, damaging homes and infrastructure.
Ukrainian President Volodymyr Zelenskyy said: “Air-defense systems and missiles are needed in Ukraine, not in a warehouse somewhere. Long-range strikes that can defend against Russian terror are needed now, not sometime later. Every day of delay, unfortunately, means more lives lost.”
Zelenskyy again urged his allies to lift restrictions on the use of long-range weapons. He has said it would help Ukraine end the war as soon as possible.