Russia has not supplied Iran its advanced S-300 anti-aircraft missile systems, an official in Russia's state arms export service was quoted as saying.

"Nothing is happening. There are no deliveries," Interfax news agency quoted Alexander Fomin, first deputy director of Russia's Federal Military and Technical Cooperation Service, as saying at an arms fair in Rio de Janeiro.

Any possible sale of the S-300 systems to Iran is a sensitive issue in Moscow's relations with the United States.

Senior Russian officials have repeatedly denied media speculation that Russia would sell Iran the systems. - Reuters