The top U.S. diplomat described "real gaps" Saturday in waning negotiations to limit Iran's Nuclear program, but steadfastly denied that any Deal struck would also bring a promise of stronger cooperation between Washington and Tehran on fighting Islamic militants. Despite the urgency to end years of negotiations by a looming **v. 24 deadline, Secretary of State John Kerry said that there was ** linkage between the Nuclear talks and even an indirect U.S.-Iran partnership to combat the Islamic State group that has ravaged much of Iraq and Syria.