Russia launched a large-scale missile attack on Wednesday, some slamming into energy facilities that caused power losses in several regions of the country, officials said.

Ukrainian President Volodymyr Zelenskyy warned allies that the defense of his nation is a litmus test for broader Western resolve.

The Russian missiles sought out targets from the Lviv region in western Ukraine near Poland to Kharkiv in northeast Ukraine bordering Russia. The state energy company Ukrenergo reported emergency power outages in six regions. It often shuts down production during attacks as a precaution.

Russia said on Monday it had downed nine Ukrainian drones that tried to attack part of the infrastructure of the TurkStream gas pipeline, through which Russian gas flows to Turkey and Europe, and called the attack an "act of energy terrorism".

A Ukrainian official says Russian forces are bypassing a key stronghold in eastern Ukraine that they have fought for months to capture and are focusing instead on cutting supply lines to it.

Ukraine introduced emergency power cuts in six regions amid what authorities described as a "massive" Russian missile strike, the national grid operator said on Wednesday.

Ukrainian officials say Russia has launched a major ballistic and cruise missile attack on regions across Ukraine

NATO member Poland scrambled fighter jets after overnight Russian missile and drone attacks on Ukraine, Warsaw's military said on Wednesday. Newsweek has reached out to Polish authorities and Russia's Defense Ministry for comment via email.