The USDA defines levy as an import charge assessed by a country or group of countries not in accordance with a definite tariff schedule. The "variable import levy" of the European Community was an example. The EC’s levy on grains varied from day to day, depending on the offering price of third-country suppliers. In USDA’s view the variable import levy is a nontariff trade barrier because, unlike a moderate customs duty or even a quota, it can completely bar imports. The Uruguay Round Agreement on Agriculture resulted in the replacement of variable levies by fixed tariffs.