Russia's attacks on Ukraine's power grid since winter have destroyed half its power-generating capacity, leading to scheduled blackouts and rolling blackouts, Ukrainian President Volodymyr Zelensky said on Tuesday.

"As a result of Russian missile and drone strikes, nine gigawatts of power have already been destroyed. The peak of electricity consumption last winter was 18 gigawatts. So half of it does not exist now," Zelensky said at a conference on the restoration of Ukraine in Berlin.

He also called on Kyiv's Western allies to supply more air defense systems, saying "it is precisely the missile and bomb terror that helps Russian troops advance on the ground."

“Air defense is the answer,” Zelensky said.

Ukraine's state energy company Ukrenergo said it was extending planned outages across the country due to increased consumption.

“Today… the period of validity of hourly shutdown schedules throughout Ukraine has been extended – restrictions will be introduced from 14:00 to 23:00,” Ukrenergo said in a statement.

On Monday, the company announced outages from 4 p.m. to 10 p.m., adding that there would be outages on Tuesday from 2 p.m. to 7 p.m.

“The reason is that consumption continues to grow. At the same time, due to extensive damage, Ukrainian power plants cannot produce as much electricity as they did before the terrorist attacks,” Ukrenergo said.

Zelensky said the strikes showed Russian President Vladimir Putin was trying to "refining the practice of destroying energy facilities," including connections between Ukraine's and Europe's energy systems.

Ukrenergo Chairman Volodymyr Kudritsky said last week that it could take "years" for Ukraine to restore its full generating capacity.

“We are dealing with an absolutely unprecedented scale of destruction,” he said, adding that thermal power plant capacity is at a “historic” minimum and “there is virtually no hydroelectric power station that has not been damaged.”

“It is technically impossible to quickly restore these damaged power plants. It will take time: weeks, often months, sometimes years,” he said in an interview published on the Ukrenergo Telegram channel.