A man sleeps on the ground as children play outside their tents at the Athens' port of Piraeus, where over 5,500 refugees and migrants stay, on Monday, March 21, 2016. Greek Prime Minister Alexis Tsipras says an international agreement to limit the number of refugees and migrants traveling to Europe cannot be properly implemented unless smugglers on the Turkish coast are stopped. (AP Photo/Thanassis Stavrakis)