The first three-way peace talks between Russia, Ukraine and the US have ended in Abu Dhabi with no apparent breakthrough, as fighting rages.

Ukrainian President Volodymyr Zelensky raised the possibility of a second meeting as early as next week, while an American official said a new round would begin on 1 February.

The two-day talks ended after waves of Russian air strikes targeted Ukraine’s badly damaged energy infrastructure, killing one person and injuring 35 others, Ukrainian officials said.

Russia accused Ukraine of attacking an ambulance in Ukrainian territory under its control, killing three medics. Later, it reported a Ukrainian missile attack on energy infrastructure in Belgorod.

The BBC could not independently verify the reports.

The talks in Abu Dhabi were the first trilateral meeting since the Kremlin launched its full-scale invasion of its neighbour in 2022.

“The central focus of the discussions was the possible parameters for ending the war,” Zelensky posted on X.

“I highly value the understanding of the need for American monitoring and oversight of the process of ending the war and ensuring genuine security.”

All sides had agreed to “report back to their capitals” and co-ordinate further steps with their leaders, he added.

“We’ve agreed that the next round begins next Sunday in Abu Dhabi again,” an unnamed US official told reporters.

The decision to hold further talks was a “good sign” and and “a lot of work” had been done over the two days of negotiations, the official added.

The Russian state news agency Ria-Novosti reported that Moscow remained open to a continuation of dialogue with Ukraine and the US.

Vitali Klitschko, mayor of the Ukrainian capital Kyiv, said one person had died and four had been wounded by Russian air strikes on Friday night, while the mayor of the city of Kharkiv reported that 31 people had been hurt there.

Kyiv’s critical infrastructure was damaged, Klitschko said, leaving 6,000 buildings without heating.

Temperatures have fallen to around -12C in parts of Ukraine. Zelensky said for his part that “the main target of the Russians” had been the energy infrastructure.

In Kharkiv, Mayor Ihor Terekhov said a maternity hospital and a hostel for displaced people had been damaged.

Ukrainian Foreign Minister Andrii Sybiha said the “brutal” Russian attack – “cynically” ordered by President Vladimir Putin – had “hit not only our people, but also the negotiation table”.

He said the “barbaric” overnight assault proved “that Putin’s place is not at the board of peace, but at the dock of the special tribunal”.

Meanwhile, Russia accused Ukraine of a “barbaric crime against the civilian population” of Kherson region, which is partially under Russian control.

Russian foreign ministry spokesperson Maria Zakharova said a clearly marked ambulance carrying a medical team from the Oleshky central district hospital had been attacked by a Ukrainian drone at the entrance to the village of Hola Prystan.

All three medics inside were killed, she said. “We emphasise that attacks on civilian medical transport are prohibited by international humanitarian law,” she added.

On Saturday evening, the governor of Belgorod, Vyacheslav Gladkov, reported that Ukraine had launched its biggest bombardment yet on the city, which lies across the border from Kharkiv.

Energy infrastructure was damaged, Gladkov said, but no casualties were caused.

US President Donald Trump said last week that Putin had accepted an invitation to join his Board of Peace – an organisation focused on ending global conflicts. Putin has not confirmed this.

Russia occupies roughly 20% of Ukraine, including parts of the eastern Donbas region. The Kremlin wants Ukraine to hand over large areas of the territory, but Ukraine has ruled this out.

In Davos, Zelensky said: “It’s all about the land. This is the issue which is not solved yet.”

He said that he had reached an agreement with Trump on future US security guarantees for Ukraine in the event of a deal.

He gave no detail but said it would need to go before US Congress and the Ukrainian parliament before signing.

The day before the talks in Abu Dhabi began, US special envoy Steve Witkoff and Trump’s son-in-law Jared Kushner met Putin in Moscow.

After the four-hour meeting, Kremlin aide Yury Ushakov said: “Vladimir Putin has emphasised Russia’s sincere commitment to settling the Ukraine crisis by political and diplomatic means.”

But he said “bringing about a lasting settlement would be unlikely without addressing the territorial issue based on the formula as agreed in Anchorage”.

Last August, Trump and Putin met in Anchorage, Alaska to discuss ending the war, resulting in an agreement to allow Russia to take the Donbas region and keep control of the Crimean peninsula, which it annexed in 2014.

Zelensky ruled out giving up the Donbas which is made up of Luhansk and Donetsk and is mostly occupied by Russia.