22 U.S. Code § 8806 - Imposition of sanctions with respect to foreign financial institutions that facilitate financial transactions on behalf of specially designated nationals
Except as provided in this section, the President shall prohibit the opening, and prohibit or impose strict conditions on the maintaining, in the United States of a correspondent account or a payable-through account by a foreign financial institution that the President determines has, on or after the date that is 180 days after January 2, 2013, knowingly facilitated a significant financial transaction on behalf of any Iranian person included on the list of specially designated nationals and blocked persons maintained by the Office of Foreign Assets Control of the Department of the Treasury (other than an Iranian financial institution described in subsection (b)).
The President may not impose sanctions under subsection (a) with respect to any person for conducting or facilitating a transaction for the sale of agricultural commodities, food, medicine, or medical devices to Iran or for the provision of humanitarian assistance to the people of Iran.
Except as provided in paragraph (2), subsection (a) shall apply with respect to a financial transaction for the purchase of petroleum or petroleum products from Iran only if, at the time of the transaction, a determination of the President under section 8513a(d)(4)(B) of this title that the price and supply of petroleum and petroleum products produced in countries other than Iran is sufficient to permit purchasers of petroleum and petroleum products from Iran to reduce significantly their purchases from Iran is in effect.
Subsection (a) shall not apply with respect to a financial transaction described in subparagraph (B) conducted or facilitated by a foreign financial institution if, at the time of the transaction, the exception under section 8513a(d)(4)(D)(i) of this title applies to the country with primary jurisdiction over the foreign financial institution.