"Due to the consequences of shelling... to maintain the balance between the production and consumption of electricity, a regime of emergency shutdowns will be introduced in all regions of Ukraine," Ukrenergo said on Telegram.

"In priority, electricity will be supplied to critical infrastructure facilities."

"The situation is difficult, but under control," the operator said, after Kyiv's forces announced they destroyed more than 60 out of the 70 missiles launched by Moscow.

Still, it said that "some power plants will not be able to work at full capacity for a certain time."

"Combined with the frost increasing in the next 24 hours, this will lead to a deficit of electricity in the system," it said.

Emergency repair works are ongoing, the company said.

On Monday the Russian army acknowledged "massive attack on Ukrainian military command systems and related defence, communications, energy and military facilities."

After suffering humiliating defeats during what has become the largest armed conflict in Europe since World War II, Russia began targeting Ukrainian energy infrastructure in October, causing sweeping blackouts.

Putin on Friday said Russian strikes on Ukrainian infrastructure were "inevitable".