31 CFR 510.208: Prohibited aircraft landing or vessel calling in the United States.

(a) No aircraft in which a foreign person has an interest that has landed at a place in North Korea may land at a place in the United States within 180 days after departure from North Korea.

(b) No vessel in which a foreign person has an interest that has called at a port in North Korea within the previous 180 days, and no vessel in which a foreign person has an interest that has engaged in a ship-to-ship transfer with such a vessel within the previous 180 days, may call at a port in the United States.

(c) The prohibitions in this section apply except to the extent provided by regulations, orders, directives, or licenses that may be issued pursuant to this part, and notwithstanding any contract entered into or any license or permit granted prior to the effective date.