The United Nations Security Council was briefed behind closed doors on the situation in Mosul by U.N. aid chief Stephen O’Brien and U.N. High Representative for Disarmament Affairs Kim Won-soo that Islamic State had used chemical weapons in Mosul, where the militants are fighting an offensive by U.S.-backed Iraqi forces to retake the city. The talks aim to reach a political solution to a conflict which erupted in March 2011 and has killed hundreds of thousands of people and displaced many millions.