Turkey agreed with the EU this month to take back all migrants and refugees who cross illegally to Greece in exchange for financial aid, faster visa-free travel for Turks and slightly accelerated EU membership talks.
The returns are supposed to begin on April 4 under the plan, which aims to close the main route by which a million migrants and refugees poured across the Aegean Sea to Greece in the last year before heading north mainly to Germany and Sweden.
But uncertainty remains over how many will be sent back, how they will be processed, and where they will be housed. The plan risks being overwhelmed by the continued flow of migrants to Greece, where arrivals rose sharply on March 30.
A series of steps needs to be taken by April 4 for the deal to get underway, according to people familiar with an internal European Commission report. These include legislative changes in Greece and Turkey, transport and other logistical arrangements, and clarity on how Turkey will treat non-Syrian refugees.
The report, which followed meetings in Ankara on March 30 between EU special envoy on migration Maarten Verwey and Turkish officials, called on EU member states to make public reports which portray Turkey as a "safe third country" for refugees.
That appeared to be an attempt to ease concern among rights groups and some European politicians about the legality and feasibility of the deal. They have questioned whether Turkey has sufficient safeguards in place to defend refugees' rights and whether it can be considered a safe country for them.
The first returnees are expected to be taken by boat from the Greek islands to Dikili, north of the city of Izmir on Turkey's Aegean coast, Turkish officials said. But where they will be housed in the longer term remains unclear.
"Our worries are that not just Dikili but the whole region's infrastructure is not ready if they stay here - whether it's health or education facilities. We have expressed these worries," Dikili's mayor, Mustafa Tosun said.
