The United States banned its financial institutions from serving as a conduit for Iranian transactions.
The ban, instituted Nov. 6, affects deals between foreign entities and Iranian financial institutions that must be routed through U.S. entities.
A substantial portion of the worldâ€™s finances is routed through the United States, and the rescission of Iranâ€™s â€œU-turnâ€ license to conduct such deals will further restrict its abilities to trade.
Multinational groups have said Iranâ€™s financial institutions fail to meet standards to prevent money-laundering terrorist financing, a factor cited in the U.S. Treasuryâ€™s decision.
The ban also aims to squeeze Iran further toward having the Islamic Republic end its nuclear weapons program.