Volodymyr Zelensky said on Friday that Russia intentionally waited for adverse weather conditions before attacking the country's energy system.

The Ukrainian president said that these conditions reduced the effectiveness of air defense by 20-30%.

"The main attack took place in four regions. I think the weather conditions affected our ability to repel the attacks by about 20-30%," Zelensky told reporters in Kiev.

Russian drones and missiles struck Ukrainian energy facilities overnight, cutting off electricity and water to homes and blocking a metro line across the Dnipro River.

Ukraine's Energy Ministry said 380,000 customers were still without power on Friday afternoon, Reuters reports.

"The blow is strong, but it is certainly not fatal," he said of the attacks.

The country's president stated that Ukraine has 203 energy facilities that require air defense to be protected from Russia.

He said Russian forces attempted a new attack near the town of Dobropillia, in the eastern Donetsk region, where Ukraine has achieved recent successes, but were repulsed.

"The Russians tried to organize some offensive actions. They wanted to unblock their troops, but they suffered losses and retreated," he said.

Zelensky also stated that Ukraine is awaiting clarification on the status of 10 air defense systems promised by the United States.

He said he hopes the new "coalition of the willing," the group of countries that have pledged to support Ukraine, will hold a new meeting this month.