[Greek Prime Minister Alexis Tsipras, right, speaks with European Commission President Jean-Claude Juncker as Belgian Prime Minister Charles Michel, left, speaks with French President Francois Hollande, center, during a round table meeting at an EU Summit in Brussels on Thursday, Dec. 15, 2016. European Union leaders meet Thursday in Brussels to discuss defense, migration, the conflict in Syria and Britain's plans to leave the bloc. (AP Photo/Geert Vanden Wijngaert)]BRUSSELS (AP) — A European Union summit where 27 leaders were supposed to show a united stand in exit negotiations with Britain quickly descended into discord Thursday when the EU legislature demanded a much bigger role in the Brexit talks.