Russia and Iran have entered into a contract whereby Moscow is to supply Tehran with S-300 surface-to-air missile systems.
The negotiation to seal the deal to supply Iran with air defence system has been on since June.
Russia President Vladimir Putin signed a decree sometimes in April ending the self-imposed ban on selling the S-300 system to Iran.
His decision was prompted after other world powers, including Russia, reached an interim deal with Iran on curbing its nuclear program.
“S-300, the air defence system, the contract has already been signed,” Sergei Chemezov, the chief executive of Russian state-owned defence conglomerate Rostec, was quoted by the RIA news agency as saying on Monday 9th November 2015.