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.

Russia said its air defences had repelled more than 150 drones, while an oil refinery caught on fire after a Ukrainian drone strike.

Tuesday's talks will be mediated by Steve Witkoff, President Trump's special envoy, and Jared Kushner, the president's son-in-law.

Ukraine will be represented by National Security Council secretary Rustem Umerov and President Volodymyr Zelensky's chief of staff, Kyrylo Budanov. The Russian delegation includes presidential aide Vladimir Medinsky and members of the military intelligence figures.

"I don't think we should expect any news today," said Kremlin spokesman Dmitry Peskov, adding the talks would continue on Wednesday.

Speaking to reporters aboard Air Force One, Donald Trump on Tuesday said Ukraine had "better come to the table fast."

The US President has previously signalled his impatience with the lack of swift progress in solving the four-year conflict.

Russia occupies roughly 20% of Ukraine, including parts of the eastern Donbas region. The Kremlin wants Ukraine to hand over large areas that territory, which Ukraine has ruled out.

For Kyiv, robust security guarantees from the West must come before any proposals with Russia can be agreed.

At least three energy workers were killed near the frontline city of Slovyansk in Monday's overnight attacks, Ukraine's deputy energy minister, Artem Nekrasov, announced on Telegram.

A further nine people - including children - were injured across the country, Zelensky said. More than 10 residential buildings and railway infrastructure damaged.

"Russia must be held to account for its aggression," he wrote on X, adding: "For peace to be real and just, action must target the sole source of this aggression".

Kyiv said 12 regions were hit, damaging infrastructure and leaving thousands without power in the southern city of Odesa.

DTEK, the country's largest private energy firm, said power infrastructure in the city had suffered "incredibly serious" damage, adding it would take a long time to return to a working condition.

Ukraine is facing an acute energy crisis after months of relentless Russian attacks on its infrastructure and as it struggles through a freezing winter.

It launched its own volley of attacks on Russia overnight. Officials said a fire broke out at the Ilsky oil refinery in the southern Krasnodar region after a drone strike. A reservoir storing oil products also caught fire.

The border region of Belgorod continued to come under attack, with Ukraine launching dozens of drones and causing significant damage of power infrastructure.

These latest discussions follow last month's trilateral talks in Abu Dhabi, which were the first three-way between Russia, Ukraine and the US since Moscow launched its full-scale invasion of its neighbour in 2022.

They ended with no breakthrough - although the first prisoner of war exchanges in months took place shortly after.