46 U.S.C. § 60502 — Discriminating duty on goods imported in foreign vessels or from contiguous countries

(a) Imposition of Duty. The United States adds an extra 10% "ad valorem" duty — a tax based on the value of the goods — on top of any other duties already owed, in two situations.

First, this extra duty applies to goods brought in on a vessel^* that is not a United States vessel. But it does not apply if that foreign vessel^* either: (A) has a legal right, by law or treaty, to enter U.S. ports and pay the same duties as a U.S. vessel; or (B) is owned only by U.S. citizens and becomes officially documented as a U.S. vessel before it leaves the U.S. port it entered.

Second, the extra duty applies to goods that were made in a foreign country that does not share a border with the United States, when those goods are imported from a country that does share a border with the United States. This does not apply if the goods are imported through ordinary strictly retail trade.

(b) Seizure and Forfeiture. If goods are imported without paying the duty this section requires, the government may seize both the goods and the vessel that carried them. Once seized, they can be permanently forfeited to the United States Government.