Answer:
remove barriers to trading products between the three countries
Step-by-step explanation:
In normal circumstances, Barriers often used by countries to limit the amount of products that other countries can sell in their territory. In most cases, they do this to help their local producers and reduce the amount of competition from foreign sellers.
United States, Mexico, and Canada created NAFTA to eliminate such barriers. So there will be 'almost' free charges if producers in each countries want to sell their products to the other two.