Greece could begin sending migrants back to Turkey from the start of next week, under new proposals which emerged from tense negotiations in Brussels.
Leaders of the European Union's 28 member states are being asked to approve a plan agreed by Turkey's prime minister Ahmet Davutoglu and European Council president Donald Tusk.
Under the scheme, any migrant arriving in Greece after March 20 would be given a swift individual interview to determine whether they will be allowed to remain or sent back to Turkey.
Mr Tusk's spokesman said that the agreement made clear that any removals would have to be "in full compliance with international and EU law" and that there would be no "collective expulsions".
He added: "The cut-off date is March 20 - that is on Sunday. All migrants arriving after that cut-off date will be returned after individual assessment."
The spokesman made clear that the new arrangements would come into force at the end of Sunday, so the first migrants facing return would be those crossing the Aegean Sea to the Greek islands on Monday morning.