Earlier, a source told Sputnik that Iranian Defense Minister Hossein Dehghan, who arrived in Moscow on February 15, would participate in the delivery ceremony.

This month, Hossein Dehghan announced Tehran would get Russian air defense systems by the end of the year, which in Iran ends on March 20, 2016.

The initial S-300 deal between Moscow and Tehran was signed in 2007, and envisaged the delivery of five S-300 squadrons, worth over $800 million. In 2010, the contract was put on hold by then-President Dmitry Medvedev due to the UN imposing sanctions on Iran. Tehran hit back, lodging a $4-billion lawsuit at an international court in Geneva against Russia’s Rosoboronexport arms export agency.

In April 2015, Russian President Vladimir Putin repealed the S-300 delivery ban. Russia's Foreign Minister Sergey Lavrov explained that Moscow’s voluntary embargo on S-300 deliveries was no longer necessary due to the progress in talks on Iran’s nuclear program. In October, Iran’s Defense Ministry confirmed Moscow’s readiness to deliver the S-300 system under an agreement signed between the two countries.

Iran has bought Russia’s most well-known air defense systems, its latest S-300PMU-2 Favorite, TASS reported earlier this month during the 2015 Dubai Airshow.

Sanctions against Tehran were officially lifted on January 16, after the UN nuclear watchdog confirmed, following a thorough investigation, that Iran had fulfilled all measures required under its deal with six world powers, designed to prevent Iran from developing nuclear weapons.

S-300 systems have been deployed in a number of countries, including Algeria, Azerbaijan, Belarus, Cyprus, Kazakhstan and Vietnam. Russia last supplied S-300 systems abroad in 2010, when 15 squadrons were delivered to China. Production of S-300 systems was then suspended as Almaz-Antey, the main producer of Russian air defenses, launched production of the next generation S-400 systems.

Earlier this week, Russia's Kommersant daily reported, citing unnamed sources, that Iran is also interested in buying Sukhoi Su-30SM fighters, the Mil Mi-8 and the Mil Mi-17 helicopters from Russia, along with other weapons.

This month an adviser to Iran’s supreme leader said Tehran plans to buy more Russian-made military hardware. “Iran is willing to buy additional amounts [of weapons] from Russia, and the Russian government also wants to positively respond to such requests,” Ali Akbar Velayati, adviser to Iran’s Supreme Leader Ayatollah Ali Khamenei, said during his four-day visit to Moscow in February, according to RIA Novosti.