In addition, there is a provision that the agreement itself must be reviewed every six years by the three nations, with a 16-year forfeiture clause. The contract may be renewed for a period of 16 years during the six-year review period.  The introduction of the Sunset clause gives more control in the organization of the future of the USMCA in the hands of national governments. However, there is concern that this could lead to greater uncertainty. Sectors such as automotive require significant investment in cross-border supply chains.  Given the dominant position of the U.S. consumer market, it is likely that this will put pressure on companies to establish more production in the United States, with a higher probability of higher production costs for these vehicles.  The U.S.-Mexico-Canada agreement is based on the North American Free Trade Agreement (NAFTA), which originally came into force on January 1, 1994. The agreement under consideration was the result of more than a year of negotiations including possible U.S. tariffs on Canada, in addition to the possibility of separate bilateral agreements.  On March 1, 2019, many organizations representing the agricultural sector in the United States announced their support for the USMCA and asked Congress to ratify the agreement. They also called on the Trump administration to continue to support NAFTA until the new trade agreement is ratified.  On March 4, House Ways and Means President Richard Neal predicted a “very hard” path through Congress for the agreement.
 Starting March 7, senior White House officials met with members of the Ways and Means House of Representatives, as well as moderate cackles from both parties, such as the Solver Caucus, the Tuesday Group and the Blue Dog Coalition, to seek ratification support. The Trump administration also withdrew from the threat to withdraw from NAFTA as negotiations with Congress continued.  On December 12, 2019, the Mexican Senate passed the revised treaty by 107-1 votes.  On April 3, 2020, Mexico announced its readiness to implement the agreement and joined Canada, although it requested that its auto industry have additional time to comply with the agreement.  The International Accreditation Service (IAS) jointly celebrates the implementation of the U.S., Mexico and Canada Trade Agreement (USMCA) because it is a better and more equitable integration of these economies for the benefit of all. The agreement provides additional support to IAS-accredited companies that are already recognized for providing testing, inspection and certification in the three USMCA markets. On December 10, 2019, the three countries reached a revised USMCA agreement. On January 29, 2020, Deputy Prime Minister and Minister of Intergovernmental Affairs Chrystia Freeland introduced the USMCA C-4 Transposition Act in the House of Commons and passed the first reading without a registered vote. On February 6, the bill passed second reading in the House of Commons by 275 votes to 28, with the Bloc Québécois voting against and all other parties voting in its favour, and it was referred to the Standing Committee on International Trade.    On 27 February 2020, the committee voted to send the bill to Parliament for third reading, without amendments. On November 30, 2018, the USMCA was signed as planned by the three parties at the G20 summit in Buenos Aires.
  Disputes over labour rights, steel and aluminum prevented ratification of this version of the agreement.   Canadian Deputy Prime Minister Chrystia Freeland, U.S. Trade Representative Robert Lightizer, and Mexican Under-Secretary of State for North America Jesus Seade officially signed a revised agreement on December 10, 2019, ratified by the three countries on March 13, 2020.