31 CFR § 594.207
Exempt transactions. — Global Terrorism Sanctions Regulations
An exemption is not a licence. Conduct this section exempts falls outside the Global Terrorism Sanctions Regulations' prohibitions altogether, so no OFAC authorization is needed for it. Read the limits with the grant: these sections routinely carve the exemption back, or point at a general licence for the part they do not cover.
Section text
The prohibitions contained in § 594.201(a)(6) and (7) do not apply to the following activities:
(a) Any authorized intelligence, law enforcement, or national security activities of the United States; or
(b) Any transaction necessary to comply with United States obligations under the Agreement between the United Nations and the United States of America regarding the Headquarters of the United States, signed at Lake Success June 26, 1947, and entered into force November 21, 1947, or the Convention on Consular Relations, done at Vienna April 24, 1963, and entered into force March 19, 1967, or any other United States international agreement.