Iraq ordered its civil aviation authority to suspend Iranian flights to Baghdad airport starting Wednesday, two sources told Reuters, after the United States threatened to sanction any airport that services Iranian carriers.

US Treasury Secretary Scott Bessent said on Monday that all Iranian airlines would be shut down on September 23 by the threat of secondary sanctions on air services providers, seven months into the war between the United States and Iran.

The Iraqi government is discussing diverting Iranian Airways flights from Baghdad to Najaf airport, two sources familiar with the matter said. They spoke on condition of anonymity because of the sensitivity of the matter.

The suspension of flights will begin Wednesday midnight.

Iranian news agency Tasnim said earlier, citing the Iranian Civil Aviation Organization, that flights from Tehran to Baghdad and Muscat have been canceled starting Wednesday and that all the remaining international flights including Istanbul will operate according to schedule.

“Iranian travelers are not currently being admitted at the airport in Oman, and consultations regarding this matter are ongoing,” a spokesperson for Iran’s Civil Aviation Organization told Iran’s semi-official ISNA news agency.

Bessent told CNBC that when Iranian airlines land at an airport, “you cannot provide them with fuel, you cannot provide them with landing services, you cannot sell them tickets, or you will be knocked out of the dollar system.”

(Reporting by Yomna Ehab, Ahmed Rasheed, Aref Mohammed and ElWely ElWelly; Editing by Sanjeev Miglani)