The US has asked for the first time whether Ukraine would withdraw from parts of the Donbas region if Kyiv were admitted to NATO, Volodymyr Zelenskyy said on Friday.
In comments that were embargoed until Saturday, the Ukrainian president stressed that any arrangement agreed in future talks would not involve recognising occupied territories as Russian.
He also claimed that the US had raised the possibility of a new security framework for Europe as part of efforts to end Russia's war in Ukraine.
He said he believed Moscow was interested in reopening broader questions about European security rather than focusing exclusively on ending the four-and-a-half-year war.
"Putin's desire to change borders in Europe is a fact. I am sure this is part of his concept of revising security guarantees in Europe," he said.
"This is dangerous because, in my view, it is precisely things like this that lead to wars or escalations."
The comments follow the latest round of peace talks in Abu Dhabi, and come after US special envoy Steve Witkoff and Donald Trump's son-in-law Jared Kushner met Putin in Moscow and Zelenskyy in Dublin.
Could Ukraine withdraw from the Donbas?
Ukraine continues to hold around a fifth of Donetsk, which is considered strategically vital as the anchor for Kyiv's eastern defence.
The core of Ukrainian-held Donetsk is a 30-mile defensive network known as the "Fortress Belt".
Ukraine is discussing a comprehensive security package with its partners that could include specific guarantees from NATO and the EU, a strong Ukrainian military and financial support for a specified period, Zelenskyy said, adding it would also include a recovery plan.
He said: "If the American side confirms precisely this to us, together with other NATO partners, then I will ask our Ukrainian society what it thinks: do we accept it or not?"
The Ukrainian president also rejected the possibility of his country committing to neutrality, and said Europe must decide its own future.
He warned that broader discussions about Europe's security could allow Putin to seek changes to NATO's military presence, including the withdrawal of American troops.
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He said Putin had raised similar ideas with then-President Joe Biden in 2021, seeking a redistribution of power in Europe and the world.
"I think Putin will bring up Finland and Sweden. I'm sure he will raise the issue of Hungary and the presence of American troops in the Baltic countries," Zelenskyy said.
Ukrainian concerns ahead of trilateral meeting
Mr Zelenskyy's warnings come as Donald Trump, Xi Jinping and Vladimir Putin are due to hold talks on Thursday at the Asia-Pacific Economic Cooperation summit in China.
German Chancellor Friedrich Merz said European leaders feared another "Anchorage moment," a reference to the Alaska summit in 2025 where they were stunned by Mr Trump's overtures to Putin in the absence of Ukrainian or European envoys.
"Please, no surprises," Mr Merz said. "Continue to play in Team Europe and in the team with Ukraine."
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