Two people were ⁠killed and dozens more wounded in a mass Russian drone attack across Ukraine overnight, President Volodymyr Zelenskyy said on Sunday, as U.S. and Ukrainian negotiators hashed out a post-war plan in the latest round of ‍peace talks.

Moscow has stepped up a winter campaign ‍of strikes on the Ukrainian energy system while also waging a battlefield offensive as Kyiv faces U.S. ⁠pressure to secure peace in the nearly four-year-old war.

Zelenskyy said the Sumy, Kharkiv, Dnipro, Zaporizhzhia, Khmelnytskyi and Odesa regions were ​targeted in an attack that included more than 200 drones. The military said 30 strikes had been recorded across 15 locations.

One person was killed in ‍the second-largest city of Kharkiv, said mayor Ihor Terekhov, who in ⁠recent days has reported significant damage to local energy facilities as a result of Russian strikes.

It was not immediately clear where the second person had died.

Major cities including the capital Kyiv have faced blackouts and ⁠cuts to heating as Russia ​pounds a power ⁠grid already hobbled by a cold snap, leaving residents struggling amid temperatures reaching -16 Celsius.

On ‍Saturday, Zelenskyy said he had ordered imports of electricity and additional power equipment to be ‌accelerated as much as possible.

Russia's latest mass attack comes as U.S. and Ukrainian officials meet in Miami to discuss security guarantees ⁠and a post-war ​recovery package for ‍Ukraine.

Washington has pushed Kyiv to agree to a peace framework that it will then present to Moscow, which ‍has been cool on the diplomatic push and has demanded major Ukrainian concessions.