"The negotiations on the subject have ended in success. I estimate that the S-300 delivery will take place in quite a short time," Iranian Deputy Foreign Minister Hossein Amir Abdollahian was quoted as saying by AFP after a Monday meeting with his Russian counterpart Mikhail Bogdanov in Moscow.
"It will be done at the soonest opportunity possible," the Iranian official noted.
The meeting came after Russian President Vladimir Putin decided in April to lift the ban on the S-300 missile system delivery to Iran.
The ban had been introduced by former Russian president Dmitry Medvedev in 2010.
Under a contract signed in 2007, Russia was required to provide Iran with at least five S-300 defense system batteries. In 2010, Medvedev cancelled the contract as he came under strong US and Israeli pressure not to go ahead with the sale of the weapons system, but his pretext was that the sale was covered by the fourth round of the UN Security Council sanctions against Iran.