Russia is modernising its S-300 missile system to supply to Iran, an adviser to Russian President Vladimir Putin said on Thursday, RIA news agency reported.
"It has partially been updated, separate elements are still being updated," said Vladimir Kozhin, a presidential adviser on military matters, referring to the S-300 system. "It will be that very S-300 complex that Iran wanted to receive."
Russia says it cancelled a contract to deliver the advanced missile system to Iran in 2010 under pressure from the West. But Putin lifted that self-imposed ban in April following an interim nuclear deal between Iran and world powers.
Moscow is hoping to reap economic and trade benefits now that a more comprehensive nuclear deal between Iran and world powers has been reached, allowing for an easing of sanctions on the Islamic republic.
Israeli Prime Minister Benjamin Netanyahu has expressed Israel's "dismay" at Russia's decision to supply the S-300s to Iran.