[A tent is set on the premises of the disused Hellenikon airport where refugees and migrants are temporarily housed in Athens]The European Union needs to come up with an alternative plan for tackling migration after Turkey threatened to back out of an accord to help stem the influx of migrants to Europe, Greece's migration minister told German daily Bild. Turkish Foreign Minister Mevlut Cavusoglu said over the weekend that Ankara would back out of the agreement with the EU if the bloc did not deliver the promised visa-free travel for Turks in return. The 28-nation EU is dependent on Ankara to enforce the deal which has sharply cut the number of refugees and migrants leaving Turkish shores for Greece.