ATHENS, Greece (AP) — An agreement between the European Union and Turkey to deport migrants currently on Greek islands back to the Turkish mainland is to take effect Monday morning.

Giorgos Kyritsis, a spokesman for the Greek government's refugee crisis committee, has told The Associated Press that Frontex, the EU's border management agency, is solely responsible for the implementation, adding that only a fraction of its promised personnel of over 2,000 is in place.

Frontex has secured three vessels that will make the short trip from the island of Lesbos to the Turkish coast starting Monday morning. It aims to deport about 750 migrants, mostly from Pakistan and Afghanistan, who either did not apply for asylum or whose applications were rejected, in the first three days.