Russia bombarded Ukraine early on Monday, killing two people in the Kiev region, authorities said on the eve of a diplomatic summit in France.
A countrywide siren was issued just after midnight, while Ukraine's military said air defences were operating in several places.
In the capital, a private medical facility caught fire as a result of the Russian strikes, killing one person and wounding three others, the State Emergency Service of Kiev said. It released images of rescuers removing people on stretchers from a gutted building.
Another pre-dawn attack on the neighbouring city of Fastiv killed one man in his 70s, according to Kiev regional governor Mykola Kalashnyk.
The strikes caused power outages in the area, with backup systems activated to maintain water and heating supplies, the official said, as temperatures dropped to -8C.
The attacks came on the eve of a meeting of European leaders in Paris as they seek a breakthrough on a peace plan Kiev says is "90 percent" ready.
To lay the groundwork, security advisers from 15 countries, including Britain, France and Germany as well as representatives from NATO and the European Union, gathered in Kiev over the weekend.
US special envoy Steve Witkoff joined the talks virtually, a Ukrainian official told AFP, though the United States' large-scale military attack on Venezuela earlier in the day overshadowed proceedings.
Another preparatory meeting, between chiefs of staff, is scheduled for Monday.
Diplomatic efforts to end Europe's deadliest conflict since World War II have gained pace in recent weeks, though both Moscow and Kiev remain at odds over the key issue of territory in a post-war settlement.
Russia, which occupies around 20 percent of Ukraine, is pushing for full control of the country's eastern Donbas region as part of a deal.
But Kiev has warned that ceding ground will embolden Moscow and said it will not sign a peace deal that fails to deter Russia from attacking again.
Trump refutes strike on Putin home
Bombarded daily and losing ground, Ukraine has responded with its own drone attacks launched towards Russian territory, targeting in particular energy infrastructure that funds the war effort.
Russia's defence ministry said it has downed Ukrainian drones targeting the Moscow region every day of 2026, and claims to have shot several hundred — an unusually high number — over the weekend.
The Kremlin published a video of a downed drone it said Ukraine had launched at the home of Russian President Vladimir Putin in the Novgorod region, adding that the property was not damaged and the leader was elsewhere at the time.
Kiev refuted the allegation, and its European allies expressed scepticism.
Asked about it on Sunday, US President Donald Trump said that "something" had happened near Putin's residence, but after reviewing the evidence, American officials did not believe it had been targeted by Ukraine.
"I don't believe that strike happened," Trump said in response to a reporter's question aboard Air Force One.
Russia has also accused Kiev of firing drones at a hotel and cafe in the Moscow-held part of Ukraine's southern Kherson region early on Thursday, killing what it said were 28 people celebrating the New Year. Ukraine says it was a military gathering.
Moscow accuses Kiev of being insincere in its peace efforts, while Ukraine says Russia is trying to scupper the diplomatic momentum to end the conflict.
Russia launched its full-scale war on Ukraine in February 2022, describing it as a "special military operation" to prevent the expansion of NATO.
Russia made bigger advances on the battlefield last year than any other year since it launched its offensive, according to an AFP analysis of data from the Institute for the Study of War.
