Yukiya Amano, the head of the United Nations atomic agency, will visit Tehran to meet Iranian President Hasan Rouhani and other top officials on Thursday in what could be a key visit in efforts to unlock a final nuclear agreement between Iran and six world powers by July 7. The agency said Wednesday discussions are expected to focus on “how to accelerate the resolution” of outstanding questions about Iran’s past nuclear work, which was widely believed to be aimed at nuclear weapons know-how. Iran denies those charges. Mr. Amano has been thrust to center-stage in the nuclear talks in recent days. He joined the negotiations in Vienna, where the International Atomic Energy Agency is based, four days running from Saturday, meeting with U.S. Secretary of State John Kerry , Iranian Foreign Minister Javad Zarif and others. The agency will have the crucial role of monitoring and overseeing any […]