Sikorski demanded that Europe be involved in the peace process.

Torsten Frey, the chief of staff to German Chancellor Friedrich Merz, also criticized the proposal. He stressed that Ukraine's withdrawal from the territories it still controls would be an unacceptable outcome.

A source, speaking on condition of anonymity, told AFP that Washington's proposals include"recognition of Crimea and other regions occupied by Russia" and a reduction in the army to 400,000 men. The US-proposed peace plan also calls for Ukraine to give up all long-range weapons.

The plan reportedly also provides for Russia to be given control over territories it has been unable to capture for nearly four years after the start of its repeated invasion.

Axios previously reported that the proposal was drafted by Trump's special envoy, Steve Witkoff, and Russian envoy Kirill Dmitriev.