The Trump administration imposed new sanctions on Iran’s rail and auto sectors, as well as foreign suppliers linked to the industries, the US Treasury Department said Thursday. The move expands Washington’s wartime economic campaign against Tehran and seeks to further restrict the flow of revenue that supports Iran’s military activities.

The sanctions come under the US Treasury’s “Operation Economic Outcast”, announced on August 24. The campaign aims to cut Tehran’s funding for the war, missile production, cyberattacks and the Islamic Revolutionary Guard Corps, or IRGC.

Washington has now extended its economic pressure from Iran’s maritime trade to its land-based transport network. A US naval blockade has disrupted Iranian oil shipments through the Strait of Hormuz, forcing Tehran to depend more heavily on road and rail networks to move petroleum, fertiliser, chemicals and other goods.

The Treasury Department said Thursday’s measures specifically target those alternative transport routes. The latest action also reflects growing pressure on Iran’s domestic industries as restrictions on maritime trade continue to affect the country’s economy.

The US designated Iran Khodro Company, known as IKCO, and SAIPA Iranian Automobile Manufacturing Company, or SAIPA. The Treasury said the two firms account for more than 90% of Iran’s domestic automobile market.

Three railway companies were also added to the sanctions list. They include the state-owned Islamic Republic of Iran Railway Company, which operates passenger and freight services, Raja Passenger Trains Company and Sherkat-E Rah Ahan-E Khamle-O-Naghle, also known as the Railway Transportation Company. The Treasury described the latter as a leading private freight railway.

Treasury Secretary Scott Bessent said the action "directly targets Iran’s enablers and lays the groundwork for the United States and our partners to drain the regime’s revenue once and for all."

The latest measures also cover foreign companies that supply Iran’s automobile sector. The Treasury targeted companies based in Indonesia, the United Arab Emirates and Turkey as part of the broader sanctions package.

The expansion comes as the US blockade of Iranian ports pushes Tehran to use alternative channels for moving essential commodities and industrial goods. The new sanctions seek to restrict those channels by targeting companies involved in Iran’s automobile and railway networks.

However, the growing pressure could also affect ordinary Iranians. Sanctions expert Brett Erickson, managing principal at Obsidian Risk Advisors, said the measures were tightening restrictions across Iran’s economy.

"The blockade squeezed Iran at sea, sanctions increasingly isolate it by ⁠air, and now Washington is constricting its economic arteries on land," said Brett Erickson, a sanctions expert and managing principal at Obsidian Risk Advisors. "You cannot choke an economy like this without choking the livelihoods of the people who depend on it."