A U.S. framework aimed at ending the war in Ukraine would leave the country more vulnerable to Russian aggression in the long term if it imposes limits on Kyiv’s armed forces, European Commission President Ursula von der Leyen warned on Sunday.

In a statement following talks on the sidelines of a G20 summit of major economies in South Africa, von der Leyen laid out a series of red lines in response to proposals being put forward by President Donald Trump’s White House. The American blueprint suggests Ukraine should make territorial concessions to Moscow, halve the size of its military and give Washington a 50 percent cut on profits from reconstruction.

“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,” von der Leyen said in the statement.

According to the Commission president, the EU has three key criteria for any peace deal: “First, borders cannot be changed by force. 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,” she said.

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

Allies have held crisis talks during the summit in South Africa and EU leaders are due to hold further discussions on Monday during a joint visit to Angola. European Council President António Costa has welcomed U.S. efforts to end the war but warned the current proposal is merely “a basis which will require additional work.”

European capitals and Ukraine say they were effectively cut out of the development of the 28-point plan, which critics say rewards Russian aggression and would leave the door open to future invasions.

Trump, meanwhile, appears to have backed away from a Thursday deadline for Ukrainian President Volodymyr Zelenskyy to accept the terms of the U.S. proposal, saying the deal is “not my final offer.”