President Donald J. Trump signed an Executive Order to counter Iran's "malign influence." The Order targeted Iran's support for terrorism and its pursuit of nuclear and intercontinental ballistic weapons.
According to the White House, the Executive Order ("Imposing Sanctions with Respect to Additional Sectors of Iran") aims to deny the Iranian government revenues that are used to support its "nuclear program, missile development, terrorism and terrorist proxy networks, and malign regional influence." This includes revenues that may be gained from specified "key sectors" of the Iranian economy, namely (i) construction, (ii) mining, (iii) manufacturing and (iv) textiles.
The Executive Order authorizes secondary sanctions against individuals or companies anywhere in the world who operate in these sectors, or who engage in one or more "significant transactions" in connection with these areas of the Iranian economy (or any others identified by the Secretary of the Treasury, in consultation with the Secretary of State). In FAQ 683, which was previously issued in connection with similar language in Executive Order 13871, OFAC advised that it may consider the "totality of the facts and circumstances" when determining whether a transaction is "significant."
OFAC also updated its Specially Designated Nationals list to include several Iran-based individuals and entities.