US Secretary of State Marco Rubio said roughly four-hour talks with a Ukrainian delegation in Florida on Sunday made "additional" progress on a revised peace plan to end the Ukraine crisis, but "there is more work to be done." Meanwhile, top US envoys will head to Moscow on Monday for further discussions, media reported.

A Chinese expert noted that although all parties increasingly desire peace as the costs of a prolonged conflict become harder to bear, existing proposals fail to address their fundamental demands. As a result, the crisis is likely to persist for some time.

"This is delicate, it's complicated," Rubio told reporters after the meeting. "There are a lot of moving parts, and obviously there's another party involved here that will have to be a part of the equation," per Xinhua.

"We don't just want to end the war, we also want to help Ukraine be safe forever," said the top US diplomat.

Rustem Umerov, secretary of Ukraine's National Security and Defense Council, described the talks as "difficult but productive."

"We have made tangible progress toward establishing a just peace," Umerov, who heads the Ukrainian negotiating team, wrote on Facebook.

The meeting was meaningful and successful, he wrote, adding that there is still a lot of work ahead and the two sides will continue consultations and coordination on further steps for the sake of peace in Ukraine.

The latest round of talks between the two sides was held in Hallandale Beach, the US state of Florida earlier in the day. Neither Rubio nor Umerov took questions from reporters after the meeting.

US President Donald Trump expressed optimism after the meeting, suggesting there was a "good chance" of a deal to end Russia's war in Ukraine, according to CNN.

Talks were "going along, and they're going along well," Trump told reporters aboard Air Force One. "I think that there's a good chance we can make a deal," he added.

Ukrainian President Volodymyr Zelensky wrote on X on Monday that "it is important that the talks have a constructive dynamic and that all issues were discussed openly and with a clear focus on ensuring Ukraine's sovereignty and national interests…We will continue working. I look forward to receiving a full report from our team during a personal meeting."

US Presidential Special Envoy Steve Witkoff and US President Donald Trump's son-in-law Jared Kushner also joined Sunday's talks and will fly to Moscow on Monday for further discussions, according to a Wall Street Journal report.

Currently, all parties involved in this crisis — Russia, Ukraine, the US and Europe — have reached a point where they can no longer sustain a prolonged war of attrition, Yang Jin, deputy secretary-general of the SCO Research Center of the Chinese Academy of Social Sciences, told the Global Times.

However, any peace process hinges on preconditions that differ sharply among the parties. Washington's 28-point peace plan and Europe's 19-point version vary substantially, while Moscow is seeking outcomes that Kiev and the West are unlikely to accept, the expert noted.

Ukraine, for its part, remains firm on issues of territorial integrity and sovereignty, leaving the parties with limited common ground for a breakthrough at this stage. Yang assessed that it is unrealistic to expect a rapid peace deal from the current round of talks.

Ukraine's European allies said that Washington's 28-point peace plan - which was seen as highly favorable to Russia - would require "additional work," according to CNN.

Putin's aide Yuri Ushakov said last week the Kremlin had received the latest version of the plan.

"This isn't an official one, but we do have the document. We haven't discussed it with anyone yet because the points in it require truly serious analysis and discussion," Ushakov said.