US treasury secretary Steven Mnuchin has told a congressional committee that the authorisation to sell commercial aircraft to Iran is being reviewed.
Mnuchin was responding to a query by House Ways and Means Committee member Peter Roskam during a hearing on 24 May, which was centred on US president Donald Trump's 2018 budget proposals.
Roskam is a vehement opponent of the agreement to supply Iran Air with commercial aircraft, and introduced a bill at the beginning of the year aimed at requiring the president to report on any illicit use of commercial aircraft for military activities.
He told Mnuchin that Boeing and Airbus have been "determined to sell to [Iranian airlines] notwithstanding the bad activities of the [Iranian government]", and that Mnuchin possess an "incredible amount of authority to fix this".
Mnuchin replied that the treasury's work on terrorism financing and intelligence is "one of the most important parts" of his role, and added that US government sanctions had pressured the Iranian authorities into negotiations.
"There's no question sanctions are what brought them to the table," he said. "I believe we could have got a better deal with them at the table."
He added: "It's correct that both in the case of Boeing and Airbus, there are licences that will be required, and they are under review."
Mnuchin told the hearing that the treasury would use "everything within [its] power" to put additional sanctions on Iran, Syria and North Korea in order to "protect American lives".