Now that a number of international sanctions against Iran have been lifted, Russia is expected to deliver its first S-300 air defense systems to its ally on Thursday, with further plans to sell up to $7 billion in offensive tanks, fighter jets and other military equipment.

Russia will host a ceremony in the southern city of Astrakhan on Thursday, which will be attended by Iranian defense minister Hossein Dehghan. The missile defense system will then be sent through the Caspian Sea to Iran, according to Sputnik News.

Iran agreed in 2007 to purchase five S-300 missile systems from Russia for $800 million, but the Kremlin froze the transaction after the United Nations Security Council placed an arms embargo on Tehran in 2010 until its nuclear program could be shown to have peaceful purposes, according to The International Business Times.

The sanctions were lifted in January in exchange for Iran agreeing to not develop an atomic weapon, as laid out in the landmark nuclear deal signed between Tehran and six world powers in July.

Moscow also plans to sell Iran an unspecified number of Sukhoi Su-30SM fighter jets, warships, diesel submarines, gunships, T-90 tanks and coastal defense systems, according to a report in Russian newspaper Kommersant obtained by NBC news.

"Iran is also interested in Russia's Bastion mobile coastal defense missile system, equipped with supersonic Yakhont anti-ship missiles, along with Mi-8/17 helicopters and other arms," according to Iranian state-run media, reported The Washington Free Beacon.

A high-ranking official in the Russian Federal Service for Military-Technical Cooperation said Wednesday that the contract for some of the arms will be signed later this year, according to Press TV.

Experts suggest that Iran may be looking to spend as much as $13 billion on Russian-made weapons, according to Sputnik.

While the air defense systems are not banned under U.N. Resolution 2231, which was passed days after the nuclear deal was signed, the resolution explicitly forbids Iran from purchasing "battle tanks, armored combat vehicles, large-caliber artillery systems, combat aircraft, attack helicopters, [and] warships" for five years, according to Fox News.