The negotiations focused „primarily on car exports, tariffs on steel and aluminum, as well as the milk, egg and poultry markets.“ A provision „prevents any party from enacting laws that restrict the cross-border flow of data.“  Compared to NAFTA, the USMCA increases environmental and labour standards and encourages domestic production of cars and trucks.  The agreement also provides up-to-date intellectual property protection, gives the U.S. more access to the Canadian milk market, imposes a quota for Canadian and Mexican auto production, and increases the customs limit for Canadians who purchase U.S. products online from $20 to $150.  The full list of differences between USMCA and ALEFTA is listed on the Website of the United States Trade Representative (USTR).  On May 11, 2018, House Of Representatives spokesman Paul Ryan set May 17 as the deadline for congressional action. This deadline was not met and the agreement with Mexico was not reached until August 27, 2018.  At that time, Canada had not approved the agreement. Mexico`s outgoing President Enrique Pea Nieto, having left office on 1 December 2018 and requiring 60 days as a review period, the deadline for making the agreed text available was set at the end of September 2018, 30 September 2018. Negotiators worked around the clock and reached an agreement less than an hour before midnight on a draft text. The next day, October 1, 2018, the USMCA text was published as an agreed document. In the 2016 U.S.
presidential election, Donald Trump`s campaign included a promise to renegotiate or eliminate NAFTA if the renegotiations fail.  After the election, Trump made a series of changes that influenced trade relations with other countries. The exit from the Paris Agreement, the cessation of participation in the Trans-Pacific Partnership negotiations and the significantly larger increase in tariffs with China were some of the steps he took, which reinforced the fact that he was serious about changing NAFTA.  Much of the debate about the virtues and errors of the USMCA resembles the debate on all free trade agreements (FTAs), such as the nature of free trade agreements as public goods, potential violations of national sovereignty and the role of commercial, labour, environmental and consumer interests in the development of the language of trade agreements. 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 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.