Canada was at risk of being left out of the new agreement, but the talks between Ottawa and Washington finally resulted in an agreement to keep all three members in the new version of the trade pact.
Mexico's top NAFTA negotiator, Economy Minister Ildefonso Guajardo, tweeted that he had instructed his deputy, Juan Carlos Baker, to hand over the text of the new agreement to the Mexican Senate late on Sunday.
If the agreement is ratified by the legislatures of the three countries and their heads of state, it will be signed on November 30, Mexican television reported Televisa.
It will be exactly one day before the inauguration of the new president of Mexico, López Obrador, known for his left positions.
The president-elect, who has not yet been sworn in, has given his blessing to the new NAFTA - which will be called the US-Mexico-Canada Agreement (USMCA).
The three countries began renegotiating NAFTA more than a year ago, at the request of Donald Trump, who criticized the deal as a presidential candidate and says it was a "fraud" to the United States that cost the country jobs. The current president of the United States campaigned with the promise of rewriting NAFTA - or getting rid of it.
Negotiations for its reformulation had lasted more than a year.
Canada's presence in the agreement has eased some politicians. "I am pleased that the Trump administration has managed to conclude an agreement to modernize NAFTA with Mexico and Canada," said Republican and US Senate Finance Chair Orrin Hatch. "NAFTA is a proven success."
NAFTA overturned most of the trade barriers between the United States, Canada and Mexico, leading to increased trade between the three countries. But Trump and other critics said he encouraged entrepreneurs to move south of the border to take advantage of low Mexican wages.
