So the US imposes an embargo on trade between the two countries.
An embargo is a type of economic sanction used in foreign policy. Usually, when a country or group of countries want to punish another for some reason, uses the embargo to cut trade, either totally or partially, with that particular state or with a group of countries. It is considered a strong diplomatic measure, which seeks to trigger a reaction from the other side.
On example of such measure is the embargo was imposed by the US on Cuba, and which has been operative since 1960.