On January 29, 2020, President Trump signed H.R. 5430, the “United States-Mexico-Canada Agreement Implementation Act,” which implements the United States-Mexico-Canada Agreement (USMCA). The USMCA is a revised and updated agreement to replace the North American Free Trade Agreement (NAFTA). The USMCA Implementation Act was approved on January 16, 2020, the in the US Senate by a vote of 89-10, sending it to the President. The House of Representatives had approved the bill on December 19, 2019 by a 385-41 vote. The administration had worked with Democratic members of Congress to resolve labor and environment concerns. As a result, it sailed through both the House of Representatives controlled by the Democrats and the Senate, controlled by Republicans. 

On June 20, 2019, the Senate of Mexico ratified the original text of the agreement (114 yes, 3 no, 3 abstentions). On December 12, 2019, Mexico’s Senate passed the revised agreement (a treaty under Mexican law) by a vote of 107–1. Mexico’s ratification procedure was completed when the President announced ratification in the Diario Oficial de la Federacion (the Federal Official Gazette) on January 21, 2020 in the Presidential Decree approving the Protocol Modifying the Treaty between the United Mexican States, the United States of America and Canada, made in Mexico City on December 10, 2019, as well as two parallel agreements between the Government of the United States Mexicans and the Government of the United States of America, held in Mexico City, on December 10, 2019. The Agreement is referred to as T-MEC in Mexico.

In Canada, an implementation bill had to be re-introduced, because the previous Parliament did not pass before Parliament was dissolved and new elections held in 2019 and because the Agreement was amended by the Protocol of Amendment to that Agreement, done at Mexico City on December 10, 2019. On January 29, 2020, Bill C-4 entitled “An Act to implement the Agreement between Canada, the United States of America and the United Mexican States” was introduced and received its first reading in the House of Commons.  On January 30, the Bill received its second reading. The Agreement is referred to a CUSMA in Canada.