EU to pitch migrant plan to Turkey but no done deal

"Tomorrow's negotiations with Turkey won't be very easy," said German Chancellor Angela Merkel, who devised the outlines of the plan with Turkish Prime Minister Ahmet Davutoglu, after EU leaders agreed a common stance on March 17.

"We're on the right track but we're not there yet," French President Francois Hollande told reporters after the first day of talks in Brussels. "I can't guarantee you a happy ending."

Even if they can overcome possible Turkish objections, Thursday's EU discussions revealed considerable doubts among the Europeans themselves over whether the deal can be made either legal in international law, or workable.

During dinner talks, leaders gave EU negotiators a mandate to conclude an accord with Turkey by which it would take back all migrants who reach Greek islands off its coast. 

In return, the EU would take in Syrian refugees direct from Turkey, increase aid for Syrians there, speed Ankara's EU membership process and a scheme to let Turks visit Europe without visas.

Much of the debate, Merkel said, focused on ensuring that a plan which has outraged human rights agencies could ensure that those returned to Turkey, a country with a patchy and worsening record on the matter, would have rights to asylum protected.

"An agreement with Turkey cannot be a blank check," Belgian Prime Minister Charles Michel warned, echoing many colleagues who face complaints that Europe is selling out to anti-immigrant nationalists at home by outsourcing its problems to the Turks.

Right outside the summit center, rights group Amnesty International had planted a large screen in the middle of Brussels' European district proclaiming "Don't trade refugees. Stop the deal."

Summit chairman Donald Tusk will begin negotiations with Davutoglu at 8:30 a.m. (0730 GMT) to prepare for a lunch meeting at which all 28 EU national leaders aim to wrap up a deal with the Turkish premier.