Iranian officials have said they will need to buy at least 400 planes in the coming years to refurbish Iran’s fleet, one of the world’s oldest. It includes some Boeing models that predate the 1979 Islamic revolution that overthrew the American-backed shah.

Image Fabrice Brégier, the president and chief executive of Airbus. Credit... Regis Duvignau/Reuters

The acquisition of modern planes is an important achievement for President Hassan Rouhani, who pledged when elected three years ago that he would negotiate a nuclear deal to help alleviate the economic privation caused by sanctions. Mr. Rouhani faces re-election next year.

Proponents of the agreements with Boeing and Airbus hope that Mr. Trump, who has described Iran as a leading sponsor of terrorism, will judge the deals by the gains they provide for employment and exports. Boeing has suggested that its planned Iran sales will support tens of thousands of jobs.

“When Boeing and Airbus come forward with these massive deals, with these jobs, these things will have an impact on the U.S. economy,” said Trita Parsi, president of the National Iranian American Council, a Washington-based group that is critical of Iran’s leaders but has called for improved ties and fewer sanctions.

“Trump made a big deal out of saving 1,000 jobs at Carrier in Indiana,” Mr. Parsi said. “It’s reasonable to assume that Trump is sensitive to economic arguments.”

Mr. Trump has sent mixed messages about his intentions on the nuclear agreement that made the aviation deals possible. He has called it a disaster but has not specified what he will seek to change. Some sanctions experts suggest he will do nothing, at least initially.

The nuclear agreement contains provisions that could snap sanctions back into place if Iran is found to be violating the terms, raising the possibility that Boeing and Airbus would have to suspend or cancel the sales and repossess planes already delivered.