Russia launched its largest aerial assault on Ukraine so far this year overnight, killing civilians and plunging much of the country into darkness — just hours after Ukrainian, Russian and U.S. officials held trilateral peace talks in Abu Dhabi.

Ukrainian Foreign Minister Andrii Sybiha said Russian President Vladimir Putin’s forces deliberately attacked while efforts at diplomacy were underway.

“Cynically, Putin ordered a brutal massive missile strike against Ukraine right while delegations are meeting in Abu Dhabi to advance the America-led peace process,” Sybiha wrote on X. Moscow’s missiles “hit not only our people, but also the negotiation table,” he added.

The Russian strikes hit Kyiv and Kharkiv hardest, Sybiha said, with dozens of ballistic and air-launched missiles and hundreds of drones used. He said Moscow again targeted energy infrastructure and residential areas, calling the assault further evidence that the Kremlin is waging “a genocidal war against civilian people.”

Ukraine’s air force said Russia fired more than 370 drones and 21 missiles overnight, while other estimates put the total number of aerial weapons at nearly 400, including hypersonic, ballistic missiles and cruise missiles.

Vitaliy Zaichenko, CEO of UkrEnergo, the state energy company, told local media that 80 percent of Ukraine will face emergency power outages on Saturday.

Explosions were reported shortly after delegations from Kyiv, Moscow and Washington wrapped up the first round of negotiations in Abu Dhabi. The discussions in Abu Dhabi are expected to continue on Saturday.

The talks brought together senior military and intelligence officials from Russia, top diplomats and security officials from Ukraine, and a U.S. delegation that includes President Donald Trump’s envoy Steve Witkoff, his son-in-law Jared Kushner and White House adviser Josh Gruenbaum.

Ukraine’s lead negotiator, Rustem Umerov, said the discussions focused on achieving a “dignified and lasting peace,” adding that further meetings were scheduled.

Ukrainian President Volodymyr Zelensky struck a more cautious tone, saying it was “too early” to draw conclusions and stressing that Russia must demonstrate a genuine willingness to end the war.