Ukrainian President Volodymyr Zelenskyy on Thursday urged his allies to bring about "regime change" in Russia, hours after a Russian drone and missile attack on Kyiv killed 16 people, including a 6-year-old boy.

The overnight strikes reduced part of a nine-story apartment block in Kyiv's western suburbs to rubble and wounded at least 150 people in the capital, authorities said.

The Russian army, meanwhile, claimed to have captured Chasiv Yar, a strategically important hillside town in eastern Ukraine where the two sides have been fiercely fighting for months.