The U.S. Treasury Department has warned foreign financial institutions that trade with the Islamic Republic of Iran or its financial sector that they may be sanctioned without prior notice.

Based on a notice issued on Monday by the Office of Foreign Assets Control of the Ministry, “Foreign financial institutions that continue to conduct transactions with Iranian financial institutions that are under sanctions may, at any time and without prior notice, be targeted and must immediately take steps to end such activities and relationships.”

The notice states that institutions that facilitate the Islamic Republic’s access to the global financial system, including by providing financial services to the government’s banks or their branches and subsidiaries in third countries, face the risk of sanctions for operating in sanctioned sectors of Iran’s economy.