Ukrainian officials said a delegation arrived in the United States on Saturday to discuss a U.S.-led diplomatic push aimed at ending the nearly four-year war, as Russian attacks again targeted Ukraine’s power grid and left parts of the country without electricity and heating in freezing temperatures.

Kyrylo Budanov, Ukrainian President Volodymyr Zelenskyy’s chief of staff, said in a Telegram post that he had arrived in the U.S. to discuss “the details of the peace agreement.” Budanov said he, along with Ukrainian negotiators Rustem Umerov and Davyd Arakhamia, would meet with U.S. envoy Steve Witkoff, President Donald Trump’s son-in-law Jared Kushner, and U.S. Army Secretary Dan Driscoll.

Zelenskyy, also posting on Telegram, said Saturday that the principal task for the Ukrainian delegation was to convey how ongoing Russian strikes undermine diplomacy. He said the strikes are “constantly worsening even the small opportunities for dialogue that existed,” and that “The American side must understand this.”

The latest comments came after Zelenskyy said Friday that the delegation would try to finalize, with U.S. officials, documents tied to a proposed peace settlement covering postwar security guarantees and economic recovery. Zelenskyy said at a Kyiv news conference with Czech President Petr Pavel that if American officials approved the proposals, the U.S. and Ukraine could sign the documents next week at the World Economic Forum in Davos, Switzerland. He added that Russia would still need to be consulted on the proposals, and organizers said Trump plans to be in Davos.

Alongside the diplomacy, Ukraine reported new damage to energy infrastructure. Ukraine’s Ministry of Energy said Russia struck energy facilities in the Kyiv and Odesa regions overnight into Saturday, and that more than 20 settlements in the Kyiv region were left without power following the attacks.

In Kharkiv, Mayor Ihor Terekhov said a Russian attack on a critical infrastructure facility in the city’s industrial district could seriously affect power and heating. Terekhov said three people were wounded and wrote that “We’re talking about serious strikes on the system that keeps the city warm and lit,” adding that the system is “constantly operating at its limits.” He said each new strike makes maintaining a stable supply more difficult and that recovery would be longer and harder.

Zelenskyy said Sunday he held a special energy coordination meeting, pointing to the most difficult situations in the cities of Kyiv, Kharkiv and Zaporizhzhia and in the surrounding regions. He said Ukraine needed to ramp up electricity imports and acquire additional equipment from partners.

Ukraine’s energy minister Denys Shmyhal said Friday that Russia conducted 612 attacks on energy targets over the last year, and that the barrage intensified in recent months as nighttime temperatures plunged to minus 18 degrees Celsius. Shmyhal said Ukraine introduced emergency measures including temporarily easing curfew restrictions to let people go whenever they needed to public heating centers set up by authorities, and that hospitals, schools and other critical infrastructure remained the top priority for electricity and heat supplies.

Officials instructed state energy companies Ukrzaliznytsia, Naftogaz and Ukroboronprom to urgently purchase imported electricity covering at least 50% of their own consumption, Shmyhal said. Russia has hammered Ukraine’s power grid, especially in winter, throughout the war, and Kyiv officials describe that strategy as “weaponizing winter.”