The output of the reactors of Iran\'s first nuclear power at Bushehr has been increased to 40 percent of its capacity, Russia\'s Atomstroyexport, the contractor of the project, said. The plant will go into full operation by the end of this year, Iranian President Mahmoud Ahmadinejad said on August 14. A senior United Nations official visited all of Iran\'s main atomic sites last week, an Iranian state news agency reported. The Islamic Republic is looking to restart talks with world powers about its disputed nuclear program. Iran\'s envoy to the UN nuclear watchdog, the IAEA, said the visit proves Tehran\'s nuclear transparency and the peaceful nature of its nuclear program. Iran is subject to four rounds of UN sanctions, as well as much tighter U.S. and European Union measures, due to its refusal to halt enriching uranium, a process that produces fuel for power stations, but can also be used to make nuclear bombs. German companies began constructing the Bushehr nuclear plant, Iran\'s first, in 1975 but stopped after a U.S. embargo was imposed on high-technology supplies to Iran following the 1979 Islamic Revolution and the subsequent U.S. Embassy siege in Tehran. Russia signed a contract with Iran in February 1998 to complete the construction. Under a bilateral agreement, which has received approval from the IAEA, Russia will initially operate the plant, supplying its fuel and taking away all the spent fuel for the next two or three years, but will eventually hand over full control to Iran.