"The contract is being implemented, They’ve begun," Kozhin said on Thursday, referring to delivery of the S-300 to Iran, Russia's state- run TASS news agency reported.
Iranian ambassador to Russia, Mehdi Sanai, said last month that Russia had started the process of delivering the missile system to Iran under a new contract between Tehran and Moscow.
Under the previous contract signed in 2007, Russia was required to provide Iran with at least five S-300 defense system batteries.
But the contract worth more than $800 million was revoked after then-President Dmitry Medvedev banned the supply of those systems to Tehran in 2010.
Later, Iran lodged a $4 billion lawsuit at an international court in Geneva against Russia’s arms export agency.
However, Russian President Vladimir Putin decided in April to lift the ban on the S-300 missile system delivery to Iran.