Ukraine and Russia agreed on Saturday to hold a second round of U.S.-brokered direct peace talks next weekend after a two-day meeting in Abu Dhabi, despite Ukrainian complaints negotiations were undermined by a barrage of deadly strikes.
The trilateral talks in the UAE will resume on Feb. 1, a U.S. official said, adding: "I think getting everyone together was a big step.
"I think it's a confirmation of the fact that, number one, a lot of progress has been made to date in really defining the details needed to get to a conclusion."
Russian and Ukrainian negotiators are last known to have met face-to-face in Istanbul last summer, in talks that ended only in deals to exchange captured soldiers.
This week was the first time they have faced each other to talk about a plan being pushed by President Donald Trump to end the nearly four-year war.
Ukrainian President Volodymyr Zelenskyy said "a lot was discussed, and it is important that the conversations were constructive."
On the eve of day two, Russian drones and missiles cut off millions from electricity in sub-zero temperatures. Kyiv accused Moscow of undermining the negotiations by launching yet another "night of Russian terror."
AFP journalists saw people running through the streets to find shelter as explosions lit up the night sky over the capital Kyiv.
After another sleepless night, weary Kyiv residents had little hope for a breakthrough in the nearly four-year war.
"They'll just say that everything is fine, that again, nothing has been agreed, and again there will be rockets," said Anastasia Tolkachov, who had to spend a night in a car park.
- 'Again and again' -
A United Arab Emirates government spokesperson said the meetings, which involved top military officers from both sides, were held in a "constructive and positive atmosphere".
The talks focused on "outstanding elements of the U.S.-proposed peace framework as well as confidence-building measures," the spokesperson said.
According to Zelenskyy, "the central focus of the discussions was the possible parameters for ending the war."
Both warring sides say the fate of territory in the eastern Donbas region is the main unresolved issue in the search for a settlement.
Over a million people in Kyiv and Chernigiv were left without electricity in sub-zero temperatures due to Russian strikes. About half of Kyiv's apartment blocks were cut off from heating, Ukrainian authorities said.
"This night in Kyiv, it's really all happening again and again," Iryna Berehova, 48, told AFP, adding: "These explosions, these sleepless nights, these worries for our children, for our safety, they are very exhausting."
"These negotiations that are taking place don't even give us any hope for the better."
The European Union, which has sent hundreds of power generators to Ukraine, has accused Moscow of "deliberately depriving civilians of heat."
Zelenskyy last week declared a state of emergency in the energy sector, which has been battered by relentless Russian strikes on heat and electricity supplies.
The Moscow-installed governor in the occupied Kherson region, Vladimir Saldo, said a Ukrainian drone strike killed three people in an ambulance van heading to a sick man.
While diplomacy to end Europe's worst conflict since World War II has gained pace again, Moscow and Kyiv appear deadlocked over the issue of territory.
- Donbas territory dispute -
Trump met Zelenskyy at the World Economic Forum in Davos on Thursday and U.S. special envoy Steve Witkoff later held talks with Russian President Vladimir Putin in the Kremlin.
Hours after Putin met Witkoff – and Trump's son-in-law Jared Kushner – in Moscow, the Kremlin said its demand that Kyiv withdraw from the eastern Donbas region still stood, calling it "a very important condition."
Kyiv rejects it. "The Donbas is a key issue," Zelenskyy told reporters on Friday, ahead of the talks in the UAE.
Zelenskyy said he and Trump had agreed on post-war security guarantees in Davos.
An initial U.S. draft drew heavy criticism in Kyiv and western Europe for hewing too closely to Moscow's demands, while Russia rejected later versions because they proposed European peacekeepers in Ukraine.
Putin has repeatedly said Moscow intends to get full control of eastern Ukraine by force if talks fail.
Trump has in the past pressured Ukraine to agree to terms that Kyiv sees as capitulation.