

Iranian President Mahmoud Ahmadinejad (c.) visits the Natanz Uranium Enrichment Facility some 200 miles (322 kilometers) south of the capital Tehran, April 8, 2008. Iranian President's Office/AP
Iranian President Mahmoud Ahmadinejad (r.) is escorted by technicians during a tour of the Tehran Research Reactor center in northern Tehran, Iran, on Feb. 15, 2012. Iran denies that it aims to produce nuclear weapons, with Supreme Leader Ayatollah Ali Khamenei calling them unIslamic and a 'sin.' But inspectors of the UN’s International Atomic Energy Agency (IAEA) say they still have questions about possible past weapons-related work, and want access to a military base at Parchin. Iranian President's Office/AP
An Iranian ballistic missile is launched during maneuvers by Iran’s Revolutionary Guard at an undisclosed location in Iran, July 3, 2012. Commanders claimed that war games carried out in July 2012 showed missiles with improved accuracy and firing capabilities, in a maneuver that Iranian media said was in response to stepped-up Western sanctions over Iran’s nuclear program. Hamed Jafarnejad/Fars News Agency/AP
In this April 9, 2007 photo, Iranian President Mahmoud Ahmadinejad, speaks at a ceremony in Iran's nuclear enrichment facility in Natanz, 186 miles south of capital Tehran, Iran. Hasan Sarbakhshian/AP
An Iranian policeman walks past the car belonging to Iranian nuclear scientist Mostafa Ahmadi-Roshan at a blast site outside a university in northern Tehran, on January 11, 2012. Ahmadi-Roshan was killed by a bomb placed on his car by a motorcyclist in Tehran, one of five Iranian scientists connected to Iran’s controversial nuclear program to be assassinated in the last two years. Iran blames the US and Israel for the killings, as part of a covert war aimed to slow its nuclear work. Sajad Safari/IIPA/AP
In this satellite image supplied by the Institute for Science and Security (ISIS), two buildings appear to be shrouded in pink tarps that ISIS says is to stop the UN nuclear agency from monitoring Iran's efforts to sanitize a site they suspect was used for weapons-related work, in this photo dated August 15, 2012, of the Parchin military complex southeast of Tehran, Iran. Previous photos taken earlier of the same site appear to show the same buildings, without a tarp and with extensive alterations undertaken as the suspected high explosives testing. The UN's International Atomic Energy Agency (IAEA) has requested immediate access to the site, but reported in late August that the apparent sanitizing had 'significantly hampered' the IAEA's investigation. ISIS/AP
Seized highly corrosion-resistant valves are seen in an unknown location January 11, 2013. Spanish police arrested two men and seized the contents of a truck bound for Iran loaded with materials destined for use in the Islamic state's nuclear program, Spain's Interior Ministry said. Spanish Police/Reuters
Iranian technicians work with foreign colleagues at the control console of the Bushehr Nuclear Power Plant, outside the southern port city of Bushehr, Iran, Nov. 30, 2009. After more than a decade of delays, the Russian-built reactor reached full capacity of 1,000 megawatts at the end of August, 2012. Mehdi Ghasemi/ISNA/AP
Iranian workers stand in front of the Bushehr nuclear power plant, about 746 miles south of Tehran, October 26, 2010. For the Iranian government, the Bushehr nuclear power plant is proof that its atomic program is aimed only at securing a modern, clean energy source for its people. Majid Asgaripour/Mehr News Agency/Reuters
A part of Arak heavy water nuclear facilities is seen, near the central city of Arak, 150 miles southwest of the capital Tehran, Iran, Jan. 15, 2011. Tehran has left UN nuclear inspectors empty-handed when it comes to addressing Western suspicions that it's conducting tests related to nuclear weapons. Mehdi Marizad/Fars News Agency/AP