According to the minister, who heads Mexico's negotiating team, since Mexico, Canada and the United States made a decision to modernize the 1994 trade deal, they have advanced on "a third" of approximately 30 chapters. "There are gaping differences", Lighthizer said in an evening statement.
"It's right down to the last conversations", he said, adding that he is "feeling positive" about the chances the three nations will reach a deal but that "it won't be done until it's done".
The talks to revamp the North American Free Trade Agreement (NAFTA) have been hung up on United States demands to increase American content in cars that receive duty free treatment in the trade bloc, and to have a sunset provision, which would require the three governments to renew the treaty after five years. But recent USA tariffs on steel and aluminum complicated the already-cold negotiations.
It rebuffed an effort from Prime Minister Justin Trudeau, Foreign Affairs Minister Chrystia Freeland, and several high-ranking staffers who were in the US on Thursday urging a quick deal.
Canada, the US and Mexico have been carrying out intense negotiations to redraft the NAFTA since August 2017 after US President Donald Trump said the deal has been unfair to the United States.
"I'm confident in saying that we have found a proposal that is broadly acceptable to the three partners and our industries on the auto side of things", he said, according to news reports.
"We are down to a point where there is a good deal on the table".
The "skinny NAFTA", Ujczo says, would fall in line with the "do no harm" pleas by USA agriculture, but he says not addressing key issues gives Democrats an advantage to say President Trump "did not fulfill his campaign promises to dairy farmers", and others.
Mexican officials - including the economy secretary, Ildefonso Guajardo, who is leading the Nafta talks - have insisted that the negotiations be confined to the content of the agreement itself, and not include immigration.
Those impending tariffs, the July 1 Mexican election, and the USA congressional calendar, had all created pressure for an imminent deal.
Mexican and Canadian officials on Thursday appeared to brush off the passage of an informal deadline set by the US Congress to reach a deal on revamping a continent-wide trade pact.
May 17 loomed as a deadline for a preliminary agreement after Paul Ryan, the speaker of the U.S. House of Representatives, last week said that for congress to approve a revamped NAFTA, an agreement in principle had to be submitted by that date, or congress would not have enough time to debate and approve it before legislative elections in November.
Some in the Canadian government have mused about the potential strategic benefits of dragging out the talks.