Ukraine's borders cannot be changed by force, its army cannot be reduced leaving it vulnerable to an attack and the European Union must have a central role in a peace deal for Ukraine, European Commission President Ursula von der Leyen said.

Von der Leyen's statement on Sunday comes as top officials from the United States, Ukraine, and national security advisers from France, Britain and Germany hold talks in Geneva on Sunday to discuss Washington's draft plan to end the war in Ukraine.

"Any credible and sustainable peace plan should first and foremost stop the killing and end the war, while not sowing the seeds for a future conflict," she said in a statement.

"We have agreed on the main elements necessary for a just and lasting peace and Ukraine's sovereignty. Let me highlight three of them. First, borders cannot be changed by force," she said.

"Second, as a sovereign nation there cannot be limitations on Ukraine's armed forces that would leave the country vulnerable to future attack and thereby also undermining European security," the statement said.

"Third, the centrality of the European Union in securing peace for Ukraine must be fully reflected. Ukraine must have the freedom and sovereign right to choose its own destiny. They have chosen a European destiny," von der Leyen said .