Herman Nackaerts, the chief nuclear inspector for the International Atomic Energy Agency, arrived with his delegation Thursday in Tehran. Iran, through its semiofficial Fars News Agency, confirmed that Nackaerts was seeking access to the Parchin facility.
Fereydoun Abbasi, the head of the Atomic Energy Organization of Iran, said early this year that "no documents or reason has been presented" to the Iranian government that would make a visit to the military complex necessary, however.
Nackaerts told Bloomberg News from Vienna this week that inspectors would welcome the chance to visit the site during their visit to Iran, however.
An IAEA team in February said it wasn't given access to the facility nor was it able to clarify unresolved issues related to possible military dimensions to the country's nuclear program.
IAEA Director General Yukiya Amano said last month he was concerned that Iran might be hiding nuclear activity from inspectors at the military complex.
Iran denies allegations it's pursuing the technology needed to develop a nuclear weapons. As a party to the Nuclear Non-Proliferation Treaty, Tehran said it has the right to engage in peaceful nuclear research.