Ukraine's President Volodymyr Zelensky has accused the Kremlin of resorting to energy terrorism as Russian troops make few gains on the battlefield.

Zelensky said 4.5 million people were without power following Russian attacks on its energy network.

In recent weeks, Russia has carried out large-scale missile and drone attacks on Ukrainian power facilities.

The strikes come as officials say Russian troops are likely to withdraw from the key southern city of Kherson.

After suffering a series of painful defeats on the battlefield, Russia has stepped up attacks in recent weeks on electricity infrastructure in cities away from the front lines.

In just the last month, a third of the country's power stations have reportedly been destroyed, according to President Zelensky.

The Ukrainian government has been forced to urge the population to try and use energy sparingly as a result.