S-300
S-300Reuters

Tehran has yet to receive a shipment of S-300 missiles from Moscow, Iran's official Mehr news agency amended Monday - after it rephrased a statement from Iranian Foreign Ministry spokesman Jaberi Ansari.

The original Mehr report includes a statement from Ansari that "the first part of this equipment has arrived in Iran and delivery of other parts will continue." Hours later, that statement was amended to read that "we had already announced that despite several times of change in time of delivery, the deal is on its path of implementation and today I should announce that the first phase of the agreement is implemented and the process will continue.”

The sale of the S-300, originally conducted in 2007, has been repeatedly delayed due to Western pressure given that UN nuclear sanctions ban the delivery to Iran.

But in April 2015, Russian President Vladimir Putin signed a decree lifting a ban on the delivery of the S-300 systems to Iran, explaining that his decision was motivated by Iran's drive to find a solution in talks over its nuclear program, which led to a controversial nuclear deal last July.

There is great concern over the shipment of the S-300 to the leading state sponsor of terror, given the advanced system's ability to shoot down missiles as well as jets, further defending Tehran's controversial nuclear program.