Ground-handling companies have stopped servicing Iraq-Iran flights at airports nationwide, bringing air travel between the two countries to a standstill, a source at Iraq’s Ministry of Transport told Shafaq News.

Menzies Aviation and National Aviation Services (NAS) said they could no longer provide the services for fear of U.S. Treasury penalties — Washington sanctioned 36 entities in Iran’s aviation sector, including 27 airlines, on September 8. Erbil and Sulaimaniya airports, in Iraqi Kurdistan, also suspended flights with Iran, according to Middle East Eye.