"The North American Free Trade Agreement (NAFTA) entered into force on January 1, 1994, establishing a free trade area as part of a comprehensive economic and trade agreement among the United States, Canada, and Mexico. President Trump has repeatedly stated that he intends to either renegotiate or withdraw from NAFTA. In May 2017, the U.S. Trade Representative (USTR) formally notified Congress of the Administration's intent to renegotiate NAFTA. Reactions to the announcement have been mixed, with some industries supporting NAFTA "modernization" as a way to address a range of trade concerns, while others are urging the need to proceed more cautiously so as to not destabilize current U.S. export markets."
CRS Report for Congress, R44875
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html