Last Friday, Russia carried out its largest air strike on Ukraine's energy system since its invasion in February 2022, damaging power units at a dam and causing blackouts for more than a million people.

Russia has described its recent attacks as part of a series of "revenge" strikes in response to Ukrainian attacks on Russian regions.

Russia has increased its use of ballistic missiles.

Defence Minister Rustem Umerov said the support of allies on air defences was crucial and that it could save thousands of lives.

"The total explosive power of combined air attacks on Ukraine since the beginning of the year exceeds 9 kilotons," he wrote on X after addressing participants via video link.

"Only 3 per cent of those Russian missiles, drones and guided bombs hit military targets while 97 per cent struck civilian infrastructure," he wrote.

Reuters was unable to verify that figure.

Russia denies targeting civilians although the war that began with its invasion of Ukraine has killed thousands of people, uprooted millions and destroyed towns and cities.

Russia has stepped up its air strikes on Ukraine this month.

Last week alone, it has used almost 190 missiles, 140 attack drones and 700 guided bombs, Ukrainian President Volodymyr Zelenskiy said earlier.

Australian Associated Press