As part of the landmark nuclear accord, economic sanctions were lifted against Iran and paved the way for Boeing and Iran Air to reach an agreement in December for 80 aircraft valued at $16.6 billion, based on list prices. Iran's government later said the deal's value was closer to $8 billion.
Iran Air CEO Farzaneh Sharafbafi maintained Thursday that the aircraft order was still safe even if the U.S. left the nuclear deal, according to an interview published in the Financial Tribune, a non-governmental Tehran-based paper. "This will not affect Boeing's contract with us," she said.
Still, there have been several attempts in Congress this year to block the plane sale.
For its part, Boeing said Friday in a statement: "We continue to follow the U.S. government's lead in all our dealings with approved Iranian airlines and will remain in close touch with U.S. regulators for any additional guidance."
Boeing's Iran Air sale involves the carrier purchasing 50 of its narrow-body 737 passenger jets and 30 of the wide-body 777 aircraft.
Iran Air also is buying 100 commercial aircraft from Boeing's rival, Airbus. Boeing has yet to deliver any of its planes to the country's flag carrier, but Airbus has already delivered at least three jets.
If the deal were to fall through, it could have ramifications for jobs on Boeing's production line and also put other Iran-related aircraft deals in jeopardy.
At the time the Iran Air deal was announced, Boeing said the "agreement will support tens of thousands of U.S. jobs directly associated with production."
In April, Boeing struck a $3 billion agreement with Iran's Aseman Airlines for 30 narrow-body 737 MAX jets. At the time, Boeing said the agreement also provided the airline with purchase rights for an additional 30 jets.
Jefferies analyst Howard Rubel said in a research note Friday, "There are some policy concerns outside of the nuclear accords that are at issue, but this should enable aircraft sales and other trade to move forward."