"The delivery of Russia's S-300 air defense missile system to Iran is in the executive stages and there are no political discussions underway in this regard; it has already been reiterated that the defense system will be delivered to Iran," Zarif told reporters on the sidelines of the Shanghai Cooperation Council (SCO) in Moscow on Thursday.

The Iranian foreign minister, meantime, pointed to the ongoing nuclear talks between Iran and the six world powers, and said, "We have spoken to the Russian and Chinese sides to bring back work to its track and achieve results by relying on Lausanne understanding and avoiding excessive demands in view of the short remaining time left to July 1 deadline."

In April, Iranian Deputy Foreign Minister Hossein Amir Abdollahian voiced satisfaction in the progressive trend of talks between Tehran and Moscow over the delivery of the Russian S-300 missile air defense system to his country.

"Negotiations on the delivery of the S-300 (missile system) to Iran have been successful," Amir Abdollahian said during a press conference after a meeting with his Russian counterpart Mikhail Bogdanov in the Russian capital, Moscow.

Amir Abdollahian also stressed that all issues surrounding the delivery of the system to Iran are progressing well.

He further noted that the delivery of S-300 to Iran will happen at the earliest opportunity possible.

In mid-April, Iranian Defense Minister Brigadier General Hossein Dehqan announced that Tehran and Moscow have worked out an agreement on the delivery of the Russian-made S-300 air defense systems to Iran and are now having final discussions over the date of the delivery.

“The agreement on the delivery of S-300 missile system has been finalized and the only remaining issue is the date of delivery now,” Brigadier General Dehqan told reporters in Moscow at the time.

Russian President Vladimir Putin on April 13 removed the ban on the delivery of the missile shield to Iran.