The head of the United Nations nuclear watchdog organization has held talks with Iranian President Hassan Rohani on that country's contested nuclear program.
International Atomic Energy Agency (IAEA) Director-General Amano then held talks with Foreign Minister Mohammad Javad Zarif and Iran's atomic agency chief, Ali Akbar Salehi.
The IAEA chief said, according to a statement, that "This has been a short visit but a useful one."
Amano arrived in Tehran late on August 16.
The visit came ahead of an August 25 deadline for Iran to provide information relevant to an IAEA inquiry into what it calls the possible military aspects of the country's nuclear program.
Iran's official IRNA news agency said Rohani told Amano that Tehran is prepared to cooperate with the IAEA's inquiry.
But Rohani said Iran will not discuss its long-range missile program.
An interim nuclear deal was struck last year.
The West fears that Iran's nuclear program could enable the country to build nuclear weapons. Iran insists its nuclear program is for peaceful purposes.