The attack knocked out heating to more than 5,600 apartment buildings in the capital, Kiev Mayor Vitali Klitschko said. Nearly 80% of the affected buildings had recently had their heating supply restored after a major Russian barrage on Jan. 9 that plunged thousands of people into a days-long blackout, he said.

Ukraine is enduring one of its coldest winters for years, with temperatures in Kiev falling to minus 20 C. At the same time, Russia has escalated its aerial attacks on the electricity supply, aiming to deny Ukrainians heat and running water and wear down their resistance almost four years after the war broke out on Feb. 24, 2022, the AP reported.

Meanwhile, Ukrainian officials are trying to keep up the momentum of US-led peace talks. A Ukrainian negotiating team arrived in the United States on Saturday. Their main task was to convey how the relentless Russian strikes are undermining diplomacy, according to Ukrainian President Volodymyr Zelensky.

The Ukrainian leader said last week that the delegation would also try to finalize with US officials documents for a proposed peace settlement that relate to postwar security guarantees and economic recovery. If American officials approve the proposals, the US and Ukraine could sign the documents at the World Economic Forum in Davos, Switzerland, this week, he said.

Kremlin spokesman Dmitry Peskov said Tuesday that presidential envoy Kirill Dmitriev plans to meet with some American representatives at Davos.

He refused to name the officials Dmitriev would meet with, but media reports said they would include US envoy Steve Witkoff and US President Donald Trump’s son-in-law, Jared Kushner.

Ukrainian Foreign Minister Andrii Sybiha said his country needs urgent assistance and additional sanctions on Russia to make Moscow change course.