Russia lifted the ban on sale of the S-300s to Iran, delivery of which was cancelled in 2010 after the UN imposed sanctions on Iran over its nuclear programme, on Monday.
The move has forced US and Israel to raise their concern after the Kremlin made the announcement to lift ban on shipping of the missile to Iran. Both the countries feared it could be used to protect Iranian nuclear sites from air strikes.
"The move Monday to end the ban on shipping the S-300 anti-aircraft missile system to Iran was prompted by the recent progress in talks over Tehran's nuclear program," Russian Foreign Minister Sergey Lavrov was quoted as saying by the CNN on Tuesday.
"We are convinced that at this stage, there's no more need of such an embargo, Russia's separate voluntary embargo," Lavrov said, media reported.
Read More: Obama reassures Israeli PM over Iran n-deal
Secretary of State John Kerry raised the US government's concerns over the sale in a phone call with Lavrov on Monday while Israel raised their concern by saying that Russian move to lift ban on sale of missile to Iran was a troubling sign.
Israel has been a vocal opponent of the Iran nuclear deal with six world powers.