Teheran has filed a lawsuit against Russia to the International Court for Moscow's refusal to supply Iran with the S-300 missile systems, Iranian ambassador to Moscow Mahmoud Reza Sajjadi told a news conference on Wednesday.

Sajjadi insisted that the S-300 shipment does not fall under the UN Security Council's resolution 1929, which embargoed supplying Iran with conventional weapons, including missiles, tanks, military helicopters, warplanes and warships.

The Iranian diplomat said they sent the lawsuit with the hope that the court would rule in favor of Iran and thus help Russia carry out such supplies.

Iran and Russia signed the S-300 contract in 2007. In September 2010 Russian President Dmitry Medvedev signed a decree banning shipments to Iran of the weapons and equipment listed in the UN resolution.

The Iranian ambassador also admonished Russian oil company Gazpromneft of delays in development of the Iranian oil field Azar.

"Gazpromneft has been delaying this process for two years, which causes a big damage to Iran," he was quoted by Interfax news agency as saying.

Gazpromneft and Iranian national oil company NIOC signed a memorandum in the end of 2009 about joint intentions to develop the Azar and Shangule oil fields.

Earlier, another Russian oil giant Lukoil abandoned its projects in Iran because of the international sanctions against Teheran.