GENEVA (Reuters) - The European Union's response to the refugee crisis will be a "defining moment" for the bloc, the head of the U.N. refugee agency Antonio Guterres said in a statement on Friday, warning that a divided EU would benefit only smugglers and traffickers. The EU needs to help more migrants enter legally, provide about 200,000 relocation places, according to a preliminary estimate, and support countries under pressure such as Greece, Hungary and Italy, he said. (Reporting by Tom Miles; Editing by Louise Ireland)