Russian troops have launched an unprecedented assault on energy infrastructure across Ukraine. The attacks came as the Kremlin's top spokesperson said for the first time his country has entered a "state of war."

The assault took place on Friday, and reportedly left more than one million buildings without power.

The deputy head of Ukraine's presidential office, Oleksiy Kuleba, says three people have been killed and 13 others injured.

Ukrainian President Volodymyr Zelenskyy said on social media that Russia fired nearly 90 missiles and deployed more than 60 drones.

Energy Minister German Galushchenko describes the bombardment as the largest ever attack on Ukraine's energy infrastructure.

He says a power line to the Russian-controlled Zaporizhzhia nuclear power plant has been severed. The International Atomic Energy Agency says backup lines are working.

A fire reportedly broke out at a hydroelectric power plant along the Dnipro River after the facility came under attack.

Ukrainian troops recently conducted strikes in Russia's western Belgorod region and elsewhere. Authorities in Moscow say Russian forces responded on Friday with a total of 49 strikes.

Moscow had been calling the invasion a "special operation". But Kremlin spokesperson Dmitry Peskov shelved the term in an interview with Russian media. He says Western participation has turned the conflict into a war.