A Russian official says Tehran and Moscow have signed a contract for the long-overdue delivery by Russia of 300 missile defense systems to Iran.

Sergei Chemezov, the chief executive of Russian state-owned defense conglomerate Rostec, was quoted by Ria Novosti as saying that the deal had been signed.

Russia committed to delivering the systems to Iran under a USD-800-million deal in 2007.

Moscow, however, refused to deliver the systems to Tehran in 2010 under the pretext that the agreement was covered by the fourth round of the United Nations Security Council sanctions against Iran over its nuclear program. The resolution bars hi-tech weapons sales to Tehran.

Following Moscow’s refusal to deliver the systems, Iran filed a complaint against the relevant Russian arms firm with the International Court of Arbitration in Geneva.

In April this year, President Vladimir Putin lifted a previous ban on the delivery of S-300 to Iran.

Iranian Defense Minister Brigadier General Hossein Dehqan said in mid-August that “all changes” that have been made to the S-300 system by the Russians over the years will be implemented on the battalions that are going to be delivered to Iran.