Greece has said it has made all necessary arrangements to implement a deal between the European Union and Turkey for the return of migrants. The deal will take effect on April 4, but it has been causing plenty of controversy with humanitarian aid organisations.

"We are at a satisfactory level of readiness so that the implementation of the agreement can begin on Monday. I can't say whether the other sides are also ready -- primarily the European side, on the level of the specialists they were supposed to send. In any case, on Monday, we are ready to proceed with the transfer of people to Turkey," said George Kiritsis, Greel Gov't Spokesman for Migrant Crisis.

Under the European Union deal with Turkey, migrants and refugees arriving after March 20 are to be held in centres on five Aegean islands. They will be sent back if their asylum applications are not accepted. In return, the EU will resettle thousands of legal Syrian refugees directly from Turkey -- one for each Syrian returned from the Greek islands. However, international humanitarian aid organisations have criticised the deal, questioning its legality. They query whether Turkey can be considered a safe country to return to, and whether the asylum process will be carried out properly and fairly.