[Medics take care of a rescued migrant at a local hospital in the Aegean resort of Didim, Turkey, Sunday, March 6, 2016. Turkey's state-run news agency says 18 migrants have drowned off the Turkish coast while trying to reach Greece. Anadolu Agency says the coast guard rescued 15 other migrants off the Aegean Sea resort of Didim. The coast guard has launched a search-and-rescue mission for other migrants believed to be missing from the accident Sunday.(AP Photo/Huseyin Caliskan)]BRUSSELS (AP) — NATO announced Sunday that it was expanding its mission to help choke off the smuggling of migrants into Europe by deploying warships in Greek and Turkish waters, using more vessels and deepening cooperation with the European Union's Frontex border agency.