Senior U.S. diplomat says more difficult to work with Russia on Syria

BRUSSELS (Reuters) - U.S. Deputy Secretary of State John J. Sullivan said in Brussels on Friday it has become harder for Washington to work with Moscow on Syria. "We've worked hard to maintain relations and a dialogue with Russia on those issues and areas where we can work cooperatively toward a common goal, Syria is one," Sullivan told journalists. "As the campaign against ISIS (Islamic State) has proceeded, it has become more challenging for us to work with the Russians on this (Syria)." Sullivan said he had not been directly engaged in negotiations of the U.N. Security Council vote on Syria on Friday. (Reporting by Alissa de Carbonnel, Writing by Gabriela Baczynska; Editing by Alison Williams)