Ukraine needs more air defences within weeks to allow repairs to the half of its power infrastructure destroyed by Russian attacks, or it will not be able to meet demand in the winter, the country's energy minister told Reuters.

German Galushchenko said Russia was intensifying its attacks on power systems, making repairs difficult and choking supplies.

Russian missile and drone attacks on Ukraine's energy sector have intensified since March, cutting out half of its generating capacity, resulting in rolling blackouts, including in the capital Kyiv.

"We have five months before the winter. If we won't be able to protect now ... we cannot do repairing. 50% alone is not enough to get through the winter," said Galushchenko.

"They still have time to attack us again and again before the winter," he added. "Even to repair something or to restart some units without air defence, it doesn't help you a lot because they will destroy it again."

The winter is when power demand in Ukraine is at its highest as temperatures drop far below zero.

Ukraine has been lobbying in particular for U.S.-made Patriot missile defences which have proved vital for Kyiv's chances of shooting down Russia's ballistic and hypersonic missiles.

Galushchenko said Ukraine needed seven to nine such systems and they were needed within weeks.

"We're living with restrictions now, even in the summer, because we cannot cover ... this destroyed generation," he said. "We cannot cover this by imports."

Galushchenko said Russia had also struck renewable energy sites, including a solar station.

He made his remarks on the sidelines of a conference in Berlin, where Ukraine sought to reinvigorate flagging Western support.

Switzerland hosts a summit this weekend to seek a path to peace in Ukraine, but it has been shunned by China and dismissed as a waste of time by Russia, which was not invited.

Ukrainian President Volodymyr Zelenskiy, who attended the Berlin conference, also addressed the German parliament, where his speech was boycotted by two parties including the far-right Alternative for Germany (AfD), whose support surged in recent European elections.

Galushchenko said Europeans who voted for pro-Russian parties had failed to grasp the threat posed by Russia.

"There is probably the expectation that would allow you to feel safe and peaceful here," he said.

"But that's a big mistake. Sometimes, it appears that it's ... far from us. Be sure that you will be next. The aggressors ... would never stop."

So far this year, Ukraine has been on the back foot as it faced delays in military aid from the United States, intensified attacks on its infrastructure and Moscow’s push to expand the frontline, 27 months after its full-scale invasion. (Additional reporting by Tom Balmforth in Kyiv; Editing by Mark Potter)