AlQa'dah 19, 1436, September 03, 2015, SPA -- The European Union expects to register more than 500,000 irregular arrivals at its outer borders this year, its president says of the migration surge challenging the bloc, dpa reported. "It is safe to assume that we will see over half a million irregular arrivals at Europe's external border this year, who are in part genuine asylum seekers from Syria and elsewhere," he tells EU ambassadors at a conference in Brussels. The 28-country bloc will meet its responsibilities under the UN Refugee Convention, but "that cannot be done if we sacrifice public order in the process," Tusk warns.