It is Canada that has proven the stumbling block in renegotiating NAFTA.
The Trump administration is closing in on a deal with Mexico to raise wages in the auto sector and push more manufacturing jobs to the United States - a major breakthrough in the renegotiation of the North American free-trade agreement.
"New President of Mexico has been an absolute gentleman", tweeted Trump, who also wrote that autoworkers and farmers "must be taken care of or there will be no deal".
Trump then sent a warning to Ottawa: "Their Tariffs and Trade Barriers are far too high".
Meanwhile, the US-Mexico NAFTA talks resumed last month but without Canada after negotiations involving all three members of one of the worlds largest trading blocs stalled in June.
Adam Austen, a spokesman for Canada's foreign minister, added: "We're glad Mexico and the USA continue to work out their bilateral issues".
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But people briefed on the talks expected Canadian officials to be brought in once U.S. -Mexico bilateral issues are cleared out of the way.
The United States has sought tougher rules on what percentage of a vehicle's components need to be built in the NAFTA region to avoid tariffs, as well as demanding that a certain number of cars and trucks be made in factories paying at least US$16 an hour. "It's the only way we'll get to a deal", Austen said.
Mexico is also prepared to agree to USA demands that 70 per cent of all steel, aluminium and glass used in vehicles and electronics come from North America, as well as rules that would reduce the amount of non-North American content in textiles, sources said.
Guajardo seemed to confirm Friday that the negotiations have been wide-ranging, though he has repeatedly described the topics as bilateral.
It is unclear why they refused to talk about the almost two-hour meeting with U.S. Trade Representative Robert Lighthizer, though sources say the low-profile Lighthizer has been irritated in the past by impromptu press conferences held by his counterparts after such sessions.
Ujczo said discussion has focused narrowly on what tariffs to impose on those Mexican-made cars that don't comply with the proposed "rules of origin". -Mexican issues were resolved, Canada could rejoin the talks to work on tri-lateral issues. -Mexican stumbling blocks. Two sources said the United States believed the Canadians' presence would make talks more hard because American officials have long found the Canadians intransigent.
NAFTA talks have dragged on almost a year, but have achieved a palpable momentum in the past few days.
The two leaders also discussed the importance of concluding a North American Free Trade Agreement (NAFTA).