Iran-US War: US Treasury Secretary Scott Bessent on Monday said all Iranian airlines will be grounded by September 23 (Wednesday), warning countries that they could be knocked out of the US dollar system if they provide Iranian airlines with "landing services, fuel or tickets".

Bessent's warning came as Washington stepped up pressure on Iran's aviation sector, threatening secondary sanctions against entities that continue providing essential services to Iranian carriers amid the escalating conflict.

"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," Bessent said, as quoted by CNN.

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But what exactly are these secondary sanctions, and how could they disrupt Iran's aviation sector?

What Are The Secondary Sanctions?

The US is seeking to put pressure on Iranian airlines not only by directly sanctioning the carriers but also by threatening companies in other countries that continue to provide them with essential aviation services. These are known as secondary sanctions, under which foreign companies can face restrictions on their access to the US financial system for doing significant business with sanctioned Iranian entities.

The sanctions could extend to airports, fuel suppliers, ground-handling companies, ticketing agents, financial institutions and other aviation service providers that deal with Iranian carriers. The US Treasury has separately warned that companies supporting Iranian airlines through aircraft transfers, cargo services, general sales-agent services or other assistance could face sanctions.

Which Iranian Airlines Are Targeted By The US?

In a press release, the US Department of the Treasury's Office of Foreign Assets Control (OFAC) on September 8 listed 27 Iranian airlines that "supported the Iranian regime's destabilising activities for the procurement and transport of weapons and the ferrying of personnel."

Air Shiraz

Asa Jet Airline

Ata Airlines Company

Atlas Aviation Group

Ava Airlines

Chabahar Airlines Company

Erwan Airline Company

Fly Kish Airlines

Fly Persia Airlines

Iran Air Tour

Iran Aseman Airlines

Jsky Airlines

Kish Airlines

Karun Airlines Company

Lad Airways

Mehr Airways

Nasim Air

Pars Oghyanous Kish Company

Qeshm Air

Raimon Airways

Saha Airlines

Sepehran Airlines

Soroush Air

Taban Airlines

Toos Airlines

Varesh Airlines

Zagros Airlines

Why Is The US Targeting Iran's Aviation Sector?

The US Treasury, in its press release, accused commercial Iranian airlines of supporting the activities linked to the Iranian regime and the Islamic Revolutionary Guard Corps (IRGC). The US Treasury said that private Iranian airlines have been used to transport weapons, personnel and illicit cargo, while also helping Tehran procure aircraft, spare parts and sensitive technology despite US sanctions.

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The US Treasury said that Iran conceals the recipient of US-origin aircraft through front companies, third-country intermediaries and complex transhipment routes, adding that the latest move is aimed at disrupting these networks by targeting not only Iranian airlines but also foreign companies providing them with essential services such as fuel, landing facilities and ticketing.