0223 GMT July 21, 2019
"Fifty of the planes are 737 and the other 30 are the long-haul 777 that will be delivered to Iran Air in a period of 10 years," said Farhad Parvaresh, chief executive of the airline, who signed the contract with Boeing officials in Tehran, IRNA reported.
It is the first deal with an American aviation firm since Iran’s Islamic Revolution, and comes in spite of fresh tensions over sanctions after US lawmakers voted earlier this month to renew measures against the country.
Roads and Urban Development Minister Abbas Akhoundi, who attended the signing ceremony, said it was a "historic" day for Iranian aviation and that the deal would create 8,000 jobs for Iranians.
"With the signing of this contract, the first important step has been taken for the modernization of the country's aviation fleet," Akhoundi said.
"The deal has a clear message for the world: We support peace and security as well as the growth of Iran based on a win-win policy," he said. "We hope that despite changes in the US administration, the country will remain loyal to its commitments."
The lack of new planes and parts has taken a severe toll on Iran's carriers over the years as nearly 1,700 people have died in a string of air disasters since 1979, according to the Flight Safety Foundation.
The Boeing deal would help modernize and expand the Iran's aging fleet that kept going by improvised parts. Most of Iran's fleet of 250 commercial planes were purchased before 1979.
"Our goal is to increase our ability to compete in the aviation industry to be able to get back our share in the transport industry in the region and the world," Akhoundi said.
Iran Air, whose website lists a fleet of 43 planes, offers direct flights to over 30 international destinations.
Boeing said in June it had signed a tentative agreement to sell 100 jets to Iran Air after Iranian statements about the deal. Iran Air is also due to finalize the purchase of 100 planes from European firm Airbus.
Fletcher Barkdull, a Boeing regional director, was in Tehran for the signing ceremony. Barkdull said that the deal was worth $16.6 billion and had been approved by the US government.
Following initial agreements earlier in the year, the Boeing and Airbus deals were given final approval by the US government in September.
The US lifted some of its sanctions on Iran under a nuclear deal that came into force in January, but many restrictions remained in place that mean companies trading with Tehran must receive approval from the US Treasury.
That includes European firms like Airbus who manufacture some of their parts in the United States.
In November, the US House of Representatives passed a bill intending to block the sale of commercial aircraft to Iran that would bar the US Treasury from issuing licenses that US banks would need to finance sales of commercial aircraft.
Congressional Republicans are making efforts to counter last year's nuclear accord between Iran, the United States and other world powers.
Iranian officials have reacted angrily to news that Washington will renew its existing sanctions in the coming days, saying it is a breach of the deal.