Trump had blamed NAFTA for the loss of American manufacturing jobs and wanted major changes to the pact, which underpins $1.2 trillion in annual trade. Photo: Christinne Muschi/Reuters

The United States-Mexico-Canada Agreement (USMCA) updates and replaces the nearly 25-year-old North American Free Trade Agreement (NAFTA), which US President Donald Trump had labeled a disaster and promised to cancel.

The rewrite "will result in freer markets, fairer trade and robust economic growth in our region," according to a joint statement from US Trade Representative Robert Lighthizer and Canada's Foreign Affairs Minister Chrystia Freeland.

After more than a year of talks, and six weeks of intense discussions, the governments were able to overcome their differences with both sides conceding some ground, but both hailing the agreement as a good deal for their citizens in the region of 500 million residents that conducts about $1 trillion in trade a year.

Canada will open its dairy market further to US producers, and Washington left unchanged the dispute settlement provisions which Ottawa demanded.

This will allow them to sign the agreement before Mexico's President Enrique Pena Nieto leaves office December 1, the date that was the cause of the last minute flurry of activity.

Under US law, the White House is required to submit the text of the trade deal to Congress 60 days before signing - and officials barely made it by midnight.