In comments broadcast today morning, Ali Akbar Salehi tells state TV in Vienna that Yukiya Amano will travel to Iran "within the next 3-4 days."
Salehi also said a 12-member team of inspectors from the international atomic energy agency, or IAEA, are scheduled to arrive in Tehran today.
Iran and world powers reached a historic nuclear deal in July that curbs Tehran's disputed nuclear program in return for the lifting of international sanctions.