The first day of trilateral talks between Russian, Ukrainian, and US delegations on a possible settlement in Ukraine in Geneva was tense, Russian news agencies quoted a source as saying on Tuesday.
The source said the talks lasted six hours and took place in different bilateral and trilateral formats. The delegations agreed to continue on Wednesday.
"We are ready to move quickly toward a worthy agreement to end the war," Zelenskiy said in his nightly address, saying he was waiting for a report from the negotiating team in Geneva. "The question for the Russians is: Just what do they want?"
Ukraine's lead negotiator Rustem Umerov, the head of the National Security and Defence Council, said in a statement that the day's talks had focused on "practical issues and the mechanics of possible decisions," without providing details.
Trump is urging Moscow and Kyiv to reach a deal to end Europe's biggest war since 1945, though Zelensky has complained that his country is facing the greatest pressure to make concessions.
Lead Ukrainian negotiator Rustem Umerov said "security and humanitarian issues" would be on the agenda.
"We are working constructively, focused and without excessive expectations," he posted on X. "Our task is to maximally advance those solutions that can bring sustainable peace closer."
Heavy airstrikes on Ukraine overnight
Ahead of the talks, Russia carried out heavy airstrikes overnight across swathes of Ukraine, inflicting severe damage to the power network in the southern port city of Odesa, which Ukrainian President Volodymyr Zelensky said left tens of thousands without heat and water.
Zelensky called for Kyiv's allies to increase pressure on Russia to reach a "real and just" peace deal via tougher sanctions and weapons supplies to Ukraine.
Trump pointed to Ukraine when asked by reporters what he expected from the talks in Geneva, which followed a morning of negotiations between US and Iranian officials at a different venue in the Swiss lakeside city.
"Well, we have big talks," Trump told reporters aboard Air Force One. "It's going to be very easy. I mean, look, so far, Ukraine better come to the table fast. That's all I'm telling you."
Russia is demanding that Ukraine cede the remaining 20% of the eastern region of Donetsk that Moscow has failed to capture - something Kyiv refuses to do.
"This time, the idea is to discuss a broader range of issues, including, in fact, the main ones. The main issues concern both the territories and everything else related to the demands we have put forward," Kremlin spokesman Dmitry Peskov told reporters on Monday.
The venue has switched to Geneva after Abu Dhabi hosted two rounds of talks that both sides described as constructive but which failed to reach any major breakthrough.
US. envoys Steve Witkoff and Jared Kushner were representing the Trump administration at the talks, a source told Reuters.
In a rare attempt to negotiate two major global crises simultaneously, they attended the morning indirect negotiations with Iranian officials in Geneva before crossing town to mediate the talks between Ukraine and Russia.
The Geneva round comes just days before the fourth anniversary, on February 24, of Russia's full-scale invasion of its much smaller neighbor. Tens of thousands of people have been killed, millions have fled their homes, and many Ukrainian cities, towns, and villages have been devastated by the conflict.
"One shouldn't trust the Russians absolutely, not even a little," said Oksana Reviakina, 41, an internally displaced person from the Russian-occupied city of Melitopol, when asked about the talks while sheltering in a Kyiv metro station during an air-raid alert.
Russia occupies about 20% of Ukraine's national territory, including Crimea and parts of the eastern Donbas region, which it seized before the 2022 invasion. Its recent airstrikes on energy infrastructure have left hundreds of thousands of Ukrainians without heating and power during the course of a harsh winter.
The Kremlin said the Russian delegation was being led by Vladimir Medinsky, an aide to President Vladimir Putin.
However, the fact that Ukrainian negotiators have accused Medinsky in the past of lecturing them about history as an excuse for Russia's invasion has further lowered expectations for any significant breakthrough in Geneva.
Military intelligence chief Igor Kostyukov will also take part in the talks, while Putin's special envoy Kirill Dmitriev will be part of a separate working group on economic issues.
Speaking at the annual Munich Security Conference on Saturday, Zelensky said he hoped the Geneva talks would prove "serious, substantive... but honestly sometimes it feels like the sides are talking about completely different things."
Kyiv's delegation is led by Rustem Umerov, the secretary of Ukraine's National Security and Defense Council, and by Zelensky's chief of staff, Kyrylo Budanov. Senior presidential aide Serhiy Kyslytsya is also present.
Before the delegation left for Geneva, Umerov said Ukraine's goal of "a sustainable and lasting peace" remained unchanged.
As well as land, Russia and Ukraine also remain far apart on issues such as who should control the Zaporizhzhia nuclear power plant and the possible role of Western troops in postwar Ukraine.