"I think we will deliver the S-300 by the end of the year,” Sergei Chemezov said Friday as quoted by RIA Novosti news agency.
“The first delivery will be in September or August.”
Chemezov also said that Iran has stressed it is only interested in purchasing S-300 PMU-1.
“They (Iranians) gave the conditions, and said they need only an S-300 PMU-1. We suggested an Antey-2500, but they said no, give us the S-300," he said
On February 17, Russian media reported that the first consignment of S-300 surface-to-air missile defense systems was to be delivered to Iran on February 18.
However, one day later, Russia’s Defense Ministry dismissed the reports and said there were still some issues that needed to be resolved.
"The beginning of deliveries of the first consignment of Favorit missile systems cannot take place since the Iranian side has not paid the price enshrined in the contract as of February 16," a high-ranking representative of the Russian Defense Ministry said at the time.
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But the contract, worth more than $800 million, was revoked after then-President Dmitry Medvedev banned the supply of those systems to Tehran in 2010.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.