Ukrainian President Volodymyr Zelensky told an international aid conference on Tuesday that Ukraine needed emergency aid for its energy sector totalling around €800 million. 

"Of course it is a very high amount, but the cost is less than the cost of a potential blackout," Zelensky told the gathering in Paris via video link. "I hope that decisions will be made accordingly."

Zelensky said that Ukraine needed transformers, equipment to repair damaged high-voltage power lines, as well as generators and gas turbines. 

"Because of the destruction of our power plants by terror attacks we will need to use more gas this winter than expected," he added.

This would require the import of two billion cubic metres of gas over the winter as well as major electricity imports from EU neighbours, he added.

Ukraine has been linked up to the common European power network since June after ending its connection to the Russian and Belarus grids.

"Generators have become as necessary as armoured vehicles and bullet-proof jackets," Zelensky added.

Ukrainian Prime Minister Denys Shmyhal also appealed for help from the 70 states and international agencies gathered in Paris for the "Standing with the Ukrainian People" conference.

"We are buying and looking for energy equipment all over the world and we ask the international community to help Ukraine," he said. 

"They (Russians) want to put us into darkness and it will fail, thanks to our partners all over the world," he added.

Moscow has switched tactics since October when it began airstrikes targeting Ukraine's energy network, plunging millions into cold and darkness at the onset of winter.