Ukrainian officials are heartened by an invitation for President Volodymyr Zelensky to meet with President Trump at Mar-a-Lago on Sunday, noting that Mr. Trump had said he was not interested in such a meeting until a peace deal was at hand.

Mr. Zelensky announced his travel plans Friday on X, posting, “We are not losing a single day. We have agreed on a meeting at the highest level — with President Trump in the near future. A lot can be decided before the New Year. Glory to Ukraine!”

Speaking later to reporters in Kyiv, Mr. Zelensky specified that the meeting would take place on Sunday and would largely concern security guarantees for Ukraine under an American 20-point peace plan that, he said, “is about 90 percent ready.” An “economic agreement” also will be discussed, Mr. Zelensky said.

The meeting will be the first, and possibly the easier, of two back-to-back summits at Mr. Trump’s Palm Beach retreat, with Prime Minister Benjamin Netanyahu of Israel expected to meet the president at Mar-a-Lago the next day.

Axios, which was first to report on the Monday meeting, said members of Mr. Trump’s team have grown increasingly frustrated with Mr. Netanyahu, whom they see as dragging his feet on the president’s Gaza peace plan.

“It’s JD, Marco, Jared, Steve, Susie. He has lost them,” Axios quotes a White House official as saying with respect to Trump aides JD Vance, Jared Kushner, Steve Witkoff and Susie Wiles. “The only one he has left is the president, who still likes him. But even he wants to see the Gaza deal moving faster than it is right now.”

The White House is anxious to move ahead with the next steps in Gaza, hoping to announce by early next month its plans for an international stabilization force and a “Board of Peace” chaired by Mr. Trump to oversee the territory’s governance and reconstruction. The administration had initially hoped to make the announcement before Christmas.

The Zelensky invitation follows an hour-long Christmas Day phone call in which the Ukrainian leader discussed details of the Trump peace plan with Messrs. Witkoff and Kushner, the lead negotiators for the American side.

Ukrainian media reported that America and Ukraine reached agreement earlier this week on several critical issues after Mr. Zelensky said he is willing to withdraw troops from some contested areas if those areas were to become a demilitarized zone monitored by international forces.

Russia, which has so far shown little interest in any peace plan that gives it less than total control of Ukraine’s eastern Donbas region, has not directly addressed the latest concession from Mr. Zelensky.

Commenting Thursday on the most recent American proposals, now being considered by President Vladimir Putin, the Russian foreign ministry spokeswoman, Maria Zakharova. said “there is slow but steady progress.”

Still, the fact that Messrs. Trump and Zelensky are meeting at all is being taken as a reason for cautious optimism in Kyiv, where news reports point to remarks made by the American president in October during a stopover in Doha on his way to a summit in Malaysia.

“You have to know that we’re going to make a deal, I’m not going to be wasting my time,” Mr. Trump said, suggesting he was not interested in meeting with either the Ukrainian or Russian leader unless a deal was close.