Although issues related to autos, such as the US push to boost North American content in vehicles, have been a major part of the negotiations, other issues, particularly a desire for more USA access to Canada's dairy market and Canadian insistence on maintaining NAFTA's dispute resolution system, are believed to be some of the major remaining sticking points.
Former federal Canadian trade official Matthew Kronby said the reported American demands indicate to him that the White House doesn't really want to strike a deal with Canada.
"Even Canadian concessions on dairy may not be enough to make the USA keep the current dispute resolutions", said Carlos Capistran and Mingzi Yi, economists at Bank of America Merrill Lynch, in a note.
As foreboding skies belied national worry over a new threat, a monstrous hurricane menacing the USA east coast, Foreign Affairs Minister Chrystia Freeland cited the memory of 9/11 as evidence of deep and friendly ties that have long bound the two countries together.
So far, Canada has been unable to obtain a guarantee from the United States that Canadians would not be hit with punitive USA auto tariffs if Ottawa agrees to a new NAFTA deal with Washington.
Mulroney said Justin Trudeau phoned him last weekend to discuss the NAFTA situation and the two spoke for an hour.
It's unclear how long the talks are scheduled for this week.
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Canada has reportedly offered to make concessions to its protected dairy industry, which has come under repeated attack from Trump, in an effort to retain Chapter 19.
A Canadian source with knowledge of the NAFTA discussions says an agreement is within reach, but getting there will require flexibility from all sides.
"It seems even if we give a lot, the USA keeps asking for more", said Mr. Kronby, an worldwide trade lawyer with Borden Ladner Gervais.
"I think it is good for him in the short term".
"We have all been dealing in good faith", he said. But a deal without Canada has virtually no chance of being passed, Mulroney said.
Wednesday was the first day that negotiations between the two countries resumed after four intensive days of talks last week ended without a deal on Friday after the mood soured.
"Maybe that helps us all put into perspective the negotiations that we're having - and also put into a little bit of historical perspective the importance and the significance of the relationship between Canada and the United States", Freeland told reporters outside the offices of her counterpart, U.S. Trade Representative Robert Lighthizer. "That's not who we are", Craft said in prepared remarks. "We continue to work hard and we are positively optimistic that we can get to a win-win-win for all three countries". Canadian officials had said previously that they are working on the assumption that they have until the end of September to make a deal.
"Forget what you read about NAFTA negotiations and Twitter wars".