Moscow pounded Ukrainian power infrastructure with drone and missile strikes on Saturday and Kyiv launched a deadly strike of its own on southwestern Russia, a day before talks involving senior European and U.S. officials aimed at ending the war were set to resume.

Russia attacked two Ukrainian ports on Friday, damaging three Turkish-owned vessels including a ship carrying food supplies, Ukrainian officials and one ship owner said, days after Moscow threatened to cut "Ukraine off from the sea".

"Russia delivered a targeted strike using a drone against the Turkish vessel 'VIVA', which was en route to Egypt carrying sunflower oil," Ukraine's navy said.

The aerial bombardment followed a night of attacks in which Russia fired three ballistic missiles and 151 drones, Ukraine’s air force said.