Russia launched a massive drone and missile attack targeting Ukraine’s two largest cities, Kyiv and Kharkiv, early on Saturday, as US, Ukrainian and Russian negotiators met in the United Arab Emirates for the second day of tripartite peace talks.

“Peace efforts? Trilateral meeting in the UAE? Diplomacy? For Ukrainians, this was another night of Russian terror,” Ukraine’s foreign minister, Andriy Sybiha, said after the latest Russian assault on critical infrastructure.

“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. His missiles hit not only our people, but also the negotiation table.”

Firefighters walk in front of trucks destroyed during Russian overnight drone and missile strikes in Kyiv. Photograph: Valentyn Ogirenko/Reuters

With Kyiv and other cities in the midst of widespread outages of heat, water and power after Russian attacks on energy infrastructure, officials in Kyiv said one person had been killed and at least 15 injured in strikes that continued until morning.

Engineers in Kyiv are facing the huge task of reconnecting apartment buildings to heating, reporting that 6,000 of the city’s apartment blocks were without heat on Saturday morning, 4,000 more than previous days, including many of which recently had been reconnected.

Initial estimates suggested that at least 1.2 million consumers were without power across the country, including 800,000 in Kyiv.

The Ukrainian air force said Russia had used 396 drones and missiles in the attacks, as officials warned that up to 80% of Ukraine now faced emergency power cuts in the immediate aftermath of the attack.

The Russian strikes, taking place in the middle of the first tripartite talks of the war, come in tandem with Russia continuing to insist it must control the eastern Donbas region of Ukraine, underlining doubts that Moscow is serious about peace.

Speaking in the aftermath of the strikes, the Ukrainian president, Volodymyr Zelenskyy, said agreements on air defence made with the US president, Donald Trump, in Davos this week must be “fully implemented”.

A car workshop and garage in Kyiv that was hit overnight. Photograph: Valentyn Ogirenko/Reuters

Zelenskyy and Trump met at the World Economic Forum on Thursday and discussed air defence support for Ukraine, although afterwards neither leader specified what was agreed.

The Kyiv mayor, Vitali Klitschko, said: “Currently, one person is known to have died and four to have been wounded,” he wrote in a social media post, adding that three of the injured had been hospitalised.

Fires broke out in several buildings hit by drone debris while heat and water services in parts of the capital were interrupted, he said.

The strikes come amid a worsening mid-winter energy crisis focused on the capital, where many have been left without heat and power for a prolonged period.

On Friday Klitschko said that about 1,940 residential buildings in the capital remained without heating after renewed attacks, adding “and this may not be the most difficult moment yet”.

According to Klitschko’s office, 600,000 residents have left the city temporarily during the January power crisis that has left entire blocks across the city in darkness.

Tymur Tkachenko, the head of Kyiv’s military administration, reported strikes in at least four districts. A medical facility was among the buildings damaged.

Kyiv has already endured two mass overnight attacks this year that have knocked out power and heating to hundreds of residential buildings. Emergency workers were still engaged in restoring services to residents, with overnight temperatures dipping to –13C (9F).

A Ukrainian emergency personnel works to extinguish a fire. Photograph: Oleksandr Magula/AFP/Getty Images

In Kharkiv, a frequent target 30km (18 miles) from the Russian border, the city’s mayor, Ihor Terekhov, said 25 drones had hit several districts over two and a half hours, with at least 14 people injured.

Writing on Telegram, Terekhov said the drones had struck a dormitory for displaced people, a hospital and a maternity hospital.

The latest attacks occurred after negotiators from Ukraine, Russia and the US completed the first of two days of peace talks aimed at finding a resolution to the nearly four-year-old war.

The first known direct contact between Ukrainian and Russian officials on the US-backed proposal began on Friday.

Ukraine’s chief negotiator, Rustem Umerov, said the discussions focused “on the parameters for ending Russia’s war and the further logic of the negotiation process”.

An initial US draft drew heavy criticism in Kyiv and western Europe for sticking too closely to Moscow’s line, while later iterations prompted pushback from Russia for floating the idea of European peacekeepers.

Both sides say the fate of territory in the eastern Donbas region is one of the main outstanding issues in the search for a settlement to a war that has killed tens of thousands, displaced millions and decimated parts of Ukraine.