U.S. says unclear if gaps in Iran nuclear talks can be bridged

VIENNA (Reuters) - Iran and six major powers are ready to start drafting a long-term agreement on curbing Tehran's nuclear programme in exchange for sanctions relief but it is unclear if they will succeed in overcoming disagreements, a U.S. official said on Wednesday. "Now we are set to start drafting," the senior administration official told reporters on condition of anonymity at the end of a two-day round of talks in Vienna between Iran and the United States, Britain, France, Germany, Russia and China. "At this point we don't know if we'll be successful in bridging those gaps," the official said. (Reporting by Louis Charbonneau and Fredrik Dahl; Editing by Sonya Hepinstall)