MOSCOW, April 14. /TASS/. Moscow expects Tehran to withdraw its lawsuit over supplies of S-300 air defense systems, Yevgeny Lukyanov, a deputy chief of the Russian Security Council, said on Tuesday.

He said that Russia "fulfills its obligation that it failed to fulfill earlier," he said.

Iran filed a $4 billion lawsuit against Russia's state-run arms export company Rosoboronexport in an international arbitration court in Geneva in April 2011 after Russia suspended the 2007 contract on the supplies of S-300 missile systems to Iran.

On Monday President Vladimir Putin ordered lifting the ban on the S-300 supplies to the Islamic Republic.

Putin's spokesman Dmitry Peskov said on Tuesday the Kremlin could name no specific dates when Russia may begin S-300 deliveries to Iran.

S-300 is defensive weapon not to be used to harm any country

The S-300 air defence launchers are a purely defensive weapon and the decision to sell them to Iran was made in an international situation very different from that in 2010, Russian Security Council Secretary Nikolai Patrushev has told the media on Tuesday.

He recalled that Russia in 2010 made a temporary decision against supplying the launchers to Iran of its own accord.

"Now the international situation has changed, so the Russian president has made a decision to implement that contract," Patrushev said.

"It should be borne in mind that S-300 is an exclusively defensive weapon and it will not be used to harm any country but serve the purpose of maintaining security," Patrushev said.