Russia on Thursday gave the strongest signal yet that it shares U.S. concerns over Iran\'s burgeoning nuclear program and called for tighter international controls to make sure Tehran isn\'t developing atomic weapons. Deputy Foreign Minister Georgy Mamedov said Russia would like Iran to sign an agreement with the U.N. nuclear watchdog, the International Atomic Energy Agency, introducing a close watch over all its nuclear facilities to make sure they aren\'t used as a cover for a nuclear weapons program. \"Along with the United States, we are calling on Iran to sign the protocol,\" Mamedov told reporters. The statement came amid Moscow\'s efforts to restore friendly ties with the United States following a bitter rift over the war in Iraq. Since 1995, when Russia signed a deal with Iran to build a nuclear reactor in the southern port city of Bushehr, Moscow has shrugged off U.S. concerns that the US$800 million deal could help Tehran build an atomic bomb. \"Our conscience is crystal clear,\" Mamedov said, denying that Russia\'s nuclear cooperation with Iran had anything to do with weapons. In turn, he accused unidentified western firms of helping Tehran acquire nuclear weapons know-how. \"There is a legend that all problems stem from Russia\'s peaceful nuclear cooperation with Iran, used as a cover for transferring nuclear weapons technology, and we categorically deny that,\" Mamedov said. \"We are trying to attract U.S. attention to the fact that some concerns about Iran\'s nuclear weapons program are related to the illegal activities of several western companies.\" He refused to provide any details, saying U.S. and Russian intelligence and nuclear experts were closely looking at the issue, exchanging information and sharing assessments. The IAEA is to submit a report in June on Iran\'s nuclear weapons program and Washington expects the agency to declare that Iran has violated the Nuclear Nonproliferation Treaty by secretly developing a uranium enrichment plant in Natanz in southern Iran. \"We are going to assist the IAEA in clearing up the situation in Iran,\" Mamedov said. \"Russia is even more concerned over nuclear proliferation than the United States. These weapons can be used in acute regional conflicts alongside the Russian border, particularly in the south.\" (AP)