<human>:  How many countries are in the Canada-United States Free Trade Agreement?
<bot>: The CUSTA is a free trade agreement between the United States, Canada, and Mexico. It was signed in 1992 and went into effect in 1994. It was the first free trade agreement between the three countries. It is a free trade agreement that eliminated tariffs on almost all goods traded between the three countries. It is still in effect today.