On Monday, the Iranian Foreign Ministry said that the first shipment of S-300 systems has already been delivered to Iran.
On Tuesday, Russian Deputy Prime Minister Smitry Rogozin confirmed the delivery.
"These deliveries are carried out along a logistics route set up by Russian and Iranian specialists. After receiving the first batch Tehran withdraws its lawsuit against Russia in the International Arbitration Court," Rogozin said.
"This announcement means that Russia fulfills its obligations. Previously, Moscow listened to Washington’s opinion on S-300 deliveries. Now, the situation has changed," the analyst said.
According to Perendzhiev, S-300 systems would play an important role in maintaining Iran’s national security because modern warfare is focused on aerial attacks and airstrikes.
Western politicians may protest over the delivery of S-300s to Iran, he added.
"At the same time, Russia needs Iran as an ally, especially in the Middle East. Tehran has been helping Moscow with fighting Daesh in Syria. Iran is also contributing to the settlement in Nagorno-Karabakh. It also helps with deterring Turkey’s aggressive steps toward Russia," he explained.
Iran is a reliable partner in supporting Russia’s national interests as well as maintaining global security, the analyst added.
"The S-300 is not an offensive weapons, Iran has the right to use it for defense," he said.
The $800 million Russia-Iran contract to deliver five Russian S-300 systems to Iran was signed in 2007. It was suspended after the adoption of UN Security Council sanctions on Iran in mid-2010. In 2011, in response to the suspension of the deal, Iran filed a $4-billion suit against Russia in the Geneva Arbitration Court. In April 2015, Russia resumed the talks on S-300 deliveries following a framework agreement on the landmark deal ensuring the peaceful nature of Tehran's nuclear program.
In July 2015, Russian Presidential Aide Vladimir Kozhin said that Russia would deliver a modernized version of the S-300 air defense system to Tehran, which was being updated for Iran's specific needs.
Russia and Iran are expected to fulfill the S-300 contracts in 2016, according to Iranian defense officials.