The Security and Prosperity Partnership of North America (SPP) is an initiative launched in 2005 by the leaders of Canada, Mexico, and the United States to promote security and prosperity through cooperation and sharing of information. One component of the prosperity agenda is a Working Group on the movement of goods which was created to pursue the following objectives: … lower the transaction costs of trade in goods by liberalizing the requirements for obtaining duty-free treatment under NAFTA, including through the reduction of “rules of origin” costs on goods traded between our countries. Each country should have in place procedures to allow speedy implementation of rules of origin modifications. Increase competitiveness by exploring additional supply chain options, such as by rationalizing minor difference in external tariffs, consistent with multilateral negotiation strategies.
Hayman, Aaron and Storer, Paul, "Streamlining of NAFTA Tariffs: Benefits for Washington State" (2009). Border Policy Research Institute Publications. 107.