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. Under the leadership of President Donald J. Trump, the United States renegotiated the North American Free Trade Agreement and replaced it with an updated and balanced agreement that works much better for North America, the U.S.-Mexico-Canada Agreement (USMCA), which came into effect on July 1, 2020. The USMCA is a mutually beneficial benefit to workers, farmers, farmers and businesses in North America. The agreement creates more balanced and reciprocal trade that supports high-paying jobs for Americans and cultivates the North American economy. On June 1, 2020, the USTR Office issued the uniform rules which are the last hurdle before the implementation of the agreement on July 1, 2020. The U.S.-Mexico-Mexico Agreement (USMCA) is a trade agreement between these parties. The USMCA replaced the North American Free Trade Agreement (NAFTA). Growing objections within Member States to U.S. trade policy and various aspects of the USMCA have had an impact on the signing and ratification process.
Mexico said it would not sign the USMCA if tariffs on steel and aluminum were maintained.  Based on the results of the November 6, 2018 U.S. election, it has been speculated that the greater power of Democrats in the House of Representatives could jeopardize the passage of the USMCA agreement.   Bill Pascrell, a senior Democrat, argued for changes to the USMCA to pass Congress.  Republicans have opposed the USMCA provisions that impose labour rights on LGBTQ and pregnant workers.  Forty Republicans in Congress have asked Mr. Trump not to sign an agreement that includes “the unprecedented integration of sexual orientation and the language of gender identity.” As a result, Trump ultimately signed a revised version that required each nation only to “policies it deems appropriate to protect workers from discrimination in the workplace” and said the United States would not be required to introduce additional non-discrimination laws.  The Canadian government expressed concern about the changes that have occurred under the USMCA agreement.  The agreed text of the agreement was signed by the heads of state and government of the three countries on 30 November 2018 as a secondary event at the 2018 G20 summit in Buenos Aires, Argentina.  The English, Spanish and French versions will also be binding and the agreement will take effect after ratification by the three states through the adoption of enabling laws.
 The USMCA is updating and replacing the 25-year-old North American Free Trade Agreement (NAFTA). Work on the new agreement took several years, had to be approved by both houses of Congress and required all three countries to certify that they were complying with the various measures of the agreement.