The CUSMA results, signed on the sidelines of the G20 of Heads of State and Government in Buenos Aires in November 2018, preserve key elements of long-term trade relations and contain new and updated provisions to address 21st century trade issues and foster opportunities for the nearly half a billion people who call North America at home. On April 3, 2020, Canada informed the United States and Mexico that it had completed its national process of ratifying the agreement.  On November 30, 2018, as planned, the USMCA was signed by all 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. «We have achieved this together at a time when it is becoming increasingly difficult to conclude trade agreements around the world,» she said. House Committee Chairman Richard Neal, a Democrat, said he did not see an «unnecessary delay» in the vote on the trade pact in plenary. On December 19, 2019, the U.S. House of Representatives passed the USMCA with multiparty support with 385 votes (Democracy 193, Republican 192) to 41 (Democracy 38, Republican 2, Independent 1).  On January 16, 2020, the U.S. Senate passed the trade agreement by 89 votes (Democrats 38, Republicans 51) to 10 (Democracy 8, Republican 1, Independent 1) and the bill was forwarded to the White House for the signature of Donald Trump.  On January 29, 2020, Trump signed the agreement (Public Law No: 116-113).
 NAFTA has been formally amended, but not the 1989 Canada-U.S. Free Trade Agreement, which is only «suspended.»   During the 2016 U.S. presidential election, Donald Trump`s campaign included a promise to renegotiate or eliminate NAFTA if the renegotiations failed.  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.