"Today, we finally end the NAFTA nightmare," Trump said during a signing ceremony on the South Lawn of the White House.
The roughly 400 invited guests included business leaders, Republican lawmakers and two top officials from Mexico: Foreign Secretary Marcelo Ebrard and Economy Secretary Graciela Marquez, Efe news reported.
But the President declined to invite any Democratic members of Congress, even though the version of the USMCA signed was the result of talks between the administration and Democrats in the House of Representatives.
The US Senate ratified the USMCA by a vote of 89-10 on January 16, about a month after the House approved the text.
Mexican lawmakers already gave their assent, so the only remaining hurdle is ratification by Canada's Parliament, scheduled to return from recess at the end of this month.
Washington, Ottawa and Mexico City initialed the USMCA in November 2018 after more than a year of negotiations spurred by Trump's demand for a new pact to replace NAFTA, which he described as "one of the worst trade deals in history."
The Democrats, who took control of the US House of Representatives in January 2019, demanded stronger environmental and labor provisions in exchange for their support.
On December 10, House Speaker Nancy Pelosi announced an agreement with the Trump administration on modifications to the USMCA and the revised text was signed hours later in Mexico City by Mexican lead negotiator Jesus Seade, US Trade Representative Robert Lighthizer and Canadian Deputy Prime Minister Chrystia Freeland.
"We have replaced a disastrous trade deal," Trump said Wednesday. "This is something we really put our heart into. It is probably the main reason why I chose to live this crazy life."
"This is a cutting edge, state-of-the-art agreement that protects and defends the people of our country," the president said.
In a report released last April, the US International Trade Commission estimated that enacting the USMCA would boost US gross domestic product by 0.35 per cent and lead to the creation of 176,000 new jobs.
A key change in the USMCA is a requirement that 75 per cent of cars be made in North America, up from 62.5 per cent under NAFTA. Additionally, between 40 per cent and 45 per cent of a vehicle's content must be produced by workers who earn at least $16 per hour, a stiffer requirement that could lead to more cars being manufactured in the US and Canada, as opposed to low-wage Mexico.
The deal also offers US dairy farmers greater access to the Canadian market and includes new provisions regarding e-commerce and intellectual property rights.
( With inputs from IANS )