Ukrainian President Volodymyr Zelenskyy says he plans to meet with President Donald Trump in Florida on Sunday, a possible sign of progress in U.S.-backed talks to end the nearly four-year war between Russia and Ukraine.

“We are not losing a single day. We have agreed on a meeting at the highest level — with President Trump in the near future,” Zelenskyy wrote on X on Friday.

In a WhatsApp chat with Ukrainian journalists later Friday, Zelenskyy confirmed the meeting would take place on Sunday. He added that it is unclear “whether territorial issues will be discussed.”

U.S. officials did not respond to requests for confirmation that the presidents would meet on Sunday. Trump said in November that he would only meet with Zelenskyy or Putin if a deal was reached or in its “final stages.”

The announcement came a day after Zelenskyy said he had held a “good conversation” with U.S. envoy Steve Witkoff and Jared Kushner, both central to U.S.-led efforts to resolve the conflict.

Trump has made a high-level diplomatic push to end the war, but his efforts have run into Moscow and Kyiv’s widely differing positions and demands.

Putin, who launched a full-scale invasion of Russia’s much-smaller neighbor in February 2022, has not backed off of maximalist demands that would see Ukraine blocked from integrating with the West and limit its ability to defend itself.

Until Tuesday, Zelenskyy had maintained that he would be unwilling to withdraw troops from the country’s eastern industrial heartland, much of which has been occupied by Russian forces, as part of a plan to end the war.

In a news conference with Ukrainian journalists earlier this week, Zelenskyy said that he would be willing to negotiate handing over some territory if Moscow is ready to “pull back their troops accordingly” from what will become a demilitarized zone monitored by international forces.

On Thursday, Russian Foreign Ministry spokeswoman Maria Zakharova said that there had been “slow but steady progress” in the peace talks, although Russia has given no indication that it will agree to any kind of withdrawal from land it has seized.

During a closed meeting with top Russian businessmen on Wednesday, Putin said that he wants the entire Donbas region but might be open to swapping some territory controlled by Russian forces in Ukraine, according to the Russian newspaper Komersant.

Previously, Moscow has insisted that Ukraine relinquish the remaining territory it still holds in the Donbas — an ultimatum that Ukraine has rejected. Russia has captured most of Luhansk and about 70% of Donetsk — the two areas that make up the Donbas.

On the ground, Ukraine’s deputy prime minister Oleksiy Kuleba said Russian drone attacks damaged three foreign-flagged vessels in ports in Ukraine’s Odesa and Mykolaiv regions, including a vessel under the flag of Slovakia, which is a NATO member country.

“There are partial disruptions to the power supply,” Kuleba said in a statement on Telegram on Friday.

Meanwhile, Ukraine said it struck a major Russian oil refinery on Thursday using British-supplied Storm Shadow missiles.

Ukraine’s General Staff said its forces hit the Novoshakhtinsk refinery in Russia’s Rostov region. “Multiple explosions were recorded. The target was hit,” it wrote on Telegram.

Rostov regional Gov. Yuri Slyusar said a firefighter was wounded when extinguishing the fire.

Ukraine’s long-range drone strikes on Russian refineries aim to deprive Moscow of the oil export revenue it needs to pursue its full-scale invasion. Russia wants to cripple the Ukrainian power grid, seeking to deny civilians access to heat, light and running water in what Kyiv officials say is an attempt to “weaponize winter.”