US Treasury Secretary Scott Bessent has warned that all Iranian airline operations worldwide will effectively stop from today, September 23, as new American aviation sanctions take hold and threaten secondary penalties against any foreign entity that continues to service the carriers.

Speaking on CNBC on Monday, Bessent laid out the mechanism in blunt terms: airlines, airports, fuel suppliers, ground handlers, and ticketing companies worldwide now face a single choice — stop serving Iranian carriers, or lose access to the US dollar financial system.

“On September 23, all the Iranian airlines will be shut down around the world. If they land, 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.” — Scott Bessent, US Treasury Secretary, CNBC

The warning reaches far beyond the 27 airlines sanctioned directly. Any airport authority, jet-fuel supplier, ground-handling firm, or travel agency anywhere in the world that continues to service an Iranian carrier now risks being cut off from dollar-denominated banking — a penalty severe enough that several governments have already moved to comply.

The warning follows a September 8 Treasury action under Operation Economic Outcast, which sanctioned the remaining 27 Iranian airlines not previously targeted, along with foreign companies accused of supporting Iran’s aviation sector. Washington says the sector has been used to move weapons, personnel, and illicit cargo across the region.

Routes already going dark

Iran has begun adjusting operations in real time. Iranian Civil Aviation Organization spokesman Majid Akhavan announced the cancellation of flights from Tehran to Baghdad and Muscat starting from midnight Wednesday local time, after both airports said they would no longer accept Iranian aircraft.

Authorities are working to divert Baghdad-bound flights to Najaf airport in Iraq instead. Other international routes, including those to Istanbul, were reported to be operating on schedule for the time being — though airlines and passengers alike are bracing for further disruption as the deadline takes hold.

Iraq has ordered its civil aviation authority to suspend Iranian flights to Baghdad International Airport, according to sources familiar with the directive, while Oman has stopped admitting Iranian travelers at its airport pending further consultations with Tehran.

Timeline of the squeeze

Part of a wider pressure campaign

The measures form part of the Trump administration’s broader economic pressure campaign against Tehran, running parallel to the ongoing US-Iran conflict. Iranian aviation was already constrained by years of sanctions that limited access to new aircraft, spare parts, and maintenance — leaving the fleet aged and increasingly hard to insure or service even before this week’s escalation.

Passengers holding tickets on Iranian carriers have been advised to check with their airline or travel agency for the latest updates as the September 23 deadline takes effect, with further route cancellations expected in the coming days as more airports and fuel suppliers move to comply.

Khurram Ali Raza

Khurram Ali Raza covers geopolitics, sanctions, and Middle East affairs for Faith & Freedom News.