United Nations nuclear agency chief Yukiya Amano will travel to Tehran on Sunday for talks with senior Iranian officials, the Vienna-based IAEA said on Friday. The surprise development comes as Western diplomats say the International Atomic Energy Agency (IAEA) and Iran are making headway towards a framework deal on how to tackle concerns about the Islamic state’s atomic activity. Amano will “discuss issues of mutual interest with high Iranian officials,” the International Atomic Energy Agency said, noting separately that another planned Vienna meeting between the IAEA and Iran was cancelled. Amano’s visit might suggest that an agreement has been reached after more than four years of refusal by Iran to allow the agency access to sites, information and officials it seeks for its probe. Trips to Iran by an IAEA chief are rare. The last such visit was by Amano’s predecessor, Mohamed ElBaradei, in October 2009. Herman Nackaerts, head of IAEA nuclear safeguards inspections worldwide, and Assistant Director General Rafael Grossi will accompany Amano, the statement said. The rare top-level meetings in the Iranian capital take place two days before Tehran and the six global powers discuss the future of its disputed nuclear programme in Baghdad