Russian and Ukrainian delegations are set to meet in Geneva for the latest round of US-brokered talks, a week before the fourth anniversary of Moscow's full-scale invasion of Ukraine.

Expectations for a breakthrough remain low, as Moscow has not wavered from its maximalist demands for Ukrainian territory.

Russia's strikes on Ukraine are continuing on a nightly basis, further damaging the country's already battered power grid as subzero temperatures continue.

Hours before the delegations met in Switzerland, Moscow carried out a large combined aerial attack on Ukraine, hitting 12 regions with 400 drones and almost 30 missiles. At least three people were killed.

The latest attacks showed the "extent to which Russia disregards peace efforts", Ukrainian Foreign Minister Andrii Sybiha said.