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. Mexican politicians saw NAFTA as an opportunity to accelerate and block these hard-hit reforms in the Mexican economy. In addition to trade liberalization, Mexican leaders have reduced public debt, introduced a balanced budget rule, stabilized inflation and built up the country`s foreign exchange reserves. Although Mexico was hit hard by the 2008 financial crisis because of its dependence on exports to the U.S. market – the following year, Mexican exports to the United States fell by 17% and its economy fell by more than 6% – its economy rebounded fairly quickly and returned to growth in 2010. On the other hand, critics of the agreement claim that it is responsible for job losses and wage moderation in the United States, driven by low-wage competition, from companies that have relocated their production to Mexico to reduce costs and a growing trade deficit. Dean Baker of the Centre for Economic and Political Research (CEPR) and Robert Scott of the Economic Policy Institute argue that the post-NAFTA increase in imports has resulted in a loss of up to six hundred thousand U.S. jobs over two decades, although they acknowledge that some of this import growth would likely have occurred without NAFTA. For the first time, the agreement is specifically aimed at agricultural biotechnology to support 21st century innovations in agriculture.
The text covers all biotechnology, including new technologies such as gene processing, while the trans-Pacific Partnership text covered only traditional rDNA technology. In particular, the United States, Mexico and Canada have agreed on provisions to improve information exchange and cooperation on trade-related issues in agricultural biotechnology. On December 12, 2019, the Mexican Senate adopted the revised treaty by 107 votes to 1.  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.  “We have achieved this together at a time when it is becoming increasingly difficult to conclude trade agreements around the world,” she said.