OFAC FAQ #670 · Iran Sanctions
Are there exceptions to the sanctions imposed under E.O.13871?
OFAC's answer
Yes. The sanctions authorized under [E.O. 13871](https://ofac.treasury.gov/media/14146/download?inline) do not apply to transactions for the conduct of the official business of the United States Government or the United Nations (including its specialized agencies, programmes, funds, and related organizations) by employees, grantees, or contractors thereof.