The director general of the U.N. nuclear watchdog, which is investigating whether Iran carried out work related to developing an atom bomb, visited a sensitive military site during a trip to the country, the agency said on Sunday. The military site, called Parchin, has been at the center of a debate over the level of access that the International Atomic Energy Agency (IAEA) will have in policing a deal reached in July between Iran and six world powers. The IAEA is due to issue an assessment this year on "possible military dimensions" of Iran's nuclear program under a roadmap agreement accompanying that deal.