A delegation from the United Nations\' nuclear watchdog agency is studying an invitation from the Iranian government to visit the country, state media reports. Gill Tudor, a spokeswoman for the International Atomic Energy Agency, told the official Islamic Republic News Agency that the U.N. watchdog was consider Iran\'s invitation. Tudor confirmed to United Press International via e-mail that a delegation was \"working on a possible visit.\" In a November report, the IAEA expressed \"deep and increasing concern\" over what it said were \"unresolved issues\" regarding Iran\'s nuclear program. This includes the \"existence of possible military dimensions,\" the agency said. Western allies are considering tighter sanctions on Iran in part because of nuclear weapon concerns. French President Nicolas Sarkozy has described Iran\'s actions as a \"grave and urgent threat to peace.\" Iran, in a 117-page response to IAEA claims, said many of the concerns are related to outdated developments in the Iranian nuclear program. Iran in September started operations at its Bushehr nuclear plant with the help of Moscow. Russia, under an agreement with Iran, operates and supplies fuel for the Bushehr plant. The first unit at Bushehr has the capacity to generate 1,000 megawatts of power.