Boeing Co. said Tuesday, June 21 it signed an agreement with Iran Air "expressing the airline's intent" to buy its aircraft, setting up the biggest business deal between the Islamic Republic and America since the 1979 U.S. Embassy takeover in Tehran, the Associated Press reports.

Already, an Iranian official has suggested his country as a whole may purchase $25 billion in airplanes from Chicago-based Boeing, welcome news to workers on its massive assembly line north of Seattle and company stockholders.

However, the long-standing enmity between the U.S. and Iran, as well as other sanctions, still could complicate any agreement — even after last year's nuclear deal.

Boeing issued a statement to The Associated Press saying that it signed the Iran Air agreement "under authorizations from the U.S. government following a determination that Iran had met its obligations under the nuclear accord reached last summer."

"Boeing will continue to follow the lead of the U.S. government with regards to working with Iran's airlines, and any and all contracts with Iran's airlines will be contingent upon U.S. government approval," it said, according to AFP.

Boeing's statement offered no further details. Fakher Daghestani, a Dubai-based spokesman for the manufacturer, declined to elaborate.

Iran Air, the country's national carrier, said this week it wants to buy new generations of the Boeing 737, as well as the 300ER and 900 version of the Boeing 777.