Except as provided in subsection (b), if a United States financial institution has or obtains knowledge that a correspondent account established, maintained, administered, or managed by that institution for a foreign financial institution is being used by the foreign financial institution to provide significant financial services indirectly to any person, foreign government, or financial institution designated under section 9214 of this title, the United States financial institution shall ensure that such correspondent account is no longer used to provide such services.
22 U.S. Code § 9221a - Prohibition on indirect correspondent accounts
(a) In general
(b) ExceptionA United States financial institution is authorized to process transfers of funds to or from North Korea, or for the direct or indirect benefit of any person, foreign government, or financial institution that is designated under section 9214 of this title, only if the transfer—
arises from, and is ordinarily incident and necessary to give effect to, an underlying transaction that has been authorized by a specific or general license issued by the Secretary of the Treasury; and
(c) DefinitionsIn this section:
(1) Correspondent account
(2) United States financial institution