A deal between Turkey and the European Union to readmit migrants does not apply to refugees already on Greek islands but to those who arrive once the agreement is in effect, Anadolu Agency quoted EU Affairs Minister Volkan Bozkir as saying on Thursday.

The number of migrants Turkey will take back will be in the thousands or tens of thousands, not in the millions, Bozkir also told state-run Anadolu, according to its Twitter account.

He also said that candidate country Turkey will meet its obligations to win visa-free travel to the EU by May 1. The EU promised Turkey 6 billion euro in aid for Syrian war refugees and an acceleration of Ankara's long-stalled membership talks in exchange for a clampdown on illegal migration to the bloc, which experts say has hit 130,000 so far this year.