Ukrainian President Volodymyr Zelensky and US President Donald Trump are preparing to meet in Florida to hammer out a plan ‍to end the war in Ukraine, but face major differences on crucial issues and provocations from Russian air attacks.

Russia struck Kyiv and other parts of war-torn Ukraine with hundreds of missiles and drones on Saturday, local time, knocking out power and ​heat in parts of the capital.

Zelensky called it Russia’s response to the ongoing US-brokered peace efforts. Zelensky has told journalists he plans to discuss the fate of eastern Ukraine’s contested Donbas region during the Sunday meeting at Trump’s Florida residence, ⁠as well as the future of the Zaporizhzhia nuclear power plant and other topics.

Moscow has repeatedly insisted Ukraine yield all of the Donbas, even areas still under Kyiv’s control, and Russian officials have objected to other parts of the latest proposal, sparking doubts about whether Russian President Vladimir Putin would accept whatever Sunday’s talks might produce.

The Ukrainian president told Axios on Friday he still hopes to soften a US proposal for Ukrainian forces to withdraw completely from the Donbas.

Failing that, Zelensky said the entire 20-point plan, the result of weeks of negotiations, should be put to a referendum vote.

Axios said US officials viewed Zelensky’s willingness to hold a referendum as a major step forward and ‌a sign he was ​no longer ruling out territorial concessions, although he said Russia would need to agree to a 60-day ceasefire to allow Ukraine to prepare for and hold such a vote.

A recent ‍poll suggests Ukrainian voters may also reject the plan. Zelensky’s in-person meeting with Trump, scheduled for 1pm local time (5am Monday AEDT), follows weeks of diplomatic efforts.

Russia controls all of Crimea, which it annexed in 2014, and since its invasion of Ukraine nearly four years ago has taken control of about 12 per cent of its ‍territory, including about 90 per cent of Donbas, 75 per cent of the Zaporizhzhia and Kherson regions, and slivers of the Kharkiv, Sumy, Mykolaiv and Dnipropetrovsk regions, according to Russian estimates.

Putin said on December 19 he thought a peace deal should be based on conditions he set out in 2024: Ukraine withdrawing from all of the Donbas, Zaporizhzhia and Kherson regions, and Kyiv officially renouncing its aim to join NATO.

Saturday’s air attacks show Putin does not want peace, Zelensky said to reporters after arriving in Halifax, Nova Scotia, where he met with Canadian Prime Minister Mark Carney.

In a brief statement with Zelensky by his side, Carney said peace “requires a willing Russia”.

“The barbarism that we saw overnight — the attack on Kyiv — shows just how important it is that we stand with Ukraine in this difficult time,” Carney said, pledging $CAD2.5 billion ($2.73 billion) in additional economic aid to Ukraine.

European Commission President Ursula von der Leyen, who spoke with Zelensky along with other European leaders on Saturday, said on social media platform X their shared objective remained “a just and lasting peace” that preserved Ukraine’s sovereignty and territorial ‍integrity, while strengthening the country’s security and defence capabilities.

Zelensky said he would speak with European leaders again after his meeting with Trump.