German Chancellor Angela Merkel has robustly defended the EU's migrant deal with Turkey, insisting that it is the key to reducing the flow of migrants to Europe.

As for the deportations, Merkel said she is "firmly convinced that making clear we are pitting ourselves against illegal migration, is right." She said Europe cannot stand by and watch people smugglers take control.

Meanwhile, the number of new asylum applications in Germany, Europe's top destination for refugees last year, dropped 66 percent in March. However, the German Interior Minister, Thomas De Maiziere,  warned that "despite the positive development, it is too early to give a prediction for the full year."

"In December 2015, it was 120,000 people, in January 90,000, in February 60,000 and in March 20,000. Despite this positive development in the first quarter of 2016, it is currently too early to give a prognosis for the entire year. I am aware that a lot of people are waiting for one, but making such a prognosis now would not be reliable and would be impossible," Maiziere said.