Ukraine’s president says he will tell President Trump he is prepared to put painful territorial concessions to a referendum when he meets his American counterpart Sunday at Mar-a-Lago, according to a newly published interview.

However, Vlodymyr Zelensky told Axios in the interview, such a referendum will not be possible unless Russia first agrees to a 60-day ceasefire to allow the voting to take place in a secure environment.

Speaking earlier to reporters in Kyiv, Mr. Zelensky said his primary goal at the American president’s Palm Beach retreat will be to secure “legally binding security guarantees” under any peace deal that would protect his country from another Russian invasion in the future.

“And this depends primarily on President Trump,” Politico quoted him as saying. “The question is what security guarantees President Trump is ready to give to Ukraine.”

Mr. Zelensky, who secured a promise of $1.8 billion in new aid from Canada’s prime minister, Mark Carney, during a Saturday stopover in Halifax, enters the Mar-a-Lago meeting facing his country’s fourth harsh winter in war following a series of Russian airstrikes on its power grid.

Russia’s president, Vladimir Putin, “deliberately ordered a massive bombing of residential areas and critical infrastructure of Kyiv just as leaders of Ukraine and the US are preparing to meet and advance peace,” Ukraine’s foreign minister, Andrii Sybiha, wrote Saturday on X.

In his telephone interview with Axios, Mr. Zelensky said he and the Trump administration have agreed on most aspects of a tentative peace package and codified those into five documents, though a sixth may be added.

But, he said, unless he can get a better deal on territorial concessions being demanded in the eastern Donbas region, he will need to seek the approval of the Ukrainian people. Because of political, logistical and security complications, 60 days  “is the minimum” time that would be required, he said.

“It’s better to not have a referendum than have a referendum where people do not have the possibility to come and vote,” he said.

The latest version of the draft plan, amended in talks between American and Ukrainian envoys in Florida last weekend, is understood to call for Ukrainian forces to withdraw from the portion of Donbas they still control and for the area to be turned into a demilitarized zone.

Mr. Zelensky told Axios it is not yet clear to him whether Russia is willing to go along with the proposals negotiated between Washington and Kyiv. “I have some intelligence … but I’m at the moment when I want to believe only the words of leaders,” he said.

During Mr. Zelensky’s stopover in Halifax, Mr. Carney was quoted as saying there exist “the conditions — the possibility — of a just and lasting peace. But that requires a willing Russia.”

Referring to the latest aerial assault on the Ukrainian capital, Mr. Carney said,  “The barbarism that we saw overnight — the attack on Kyiv — shows just how important it is that we stand with Ukraine during this difficult time.”