And the departure would not be immediate - Trump would have to wait a required period of six months after giving notice of withdrawal before the United States would actually be able to do so - potentially causing months of economic uncertainty for some of Trump's most ardent supporters in rural areas during an election year which already presents an uphill climb for Republicans.
The Canadian dollar steadied against the greenback on Thursday after hitting a almost two-week low earlier in the session as investors weighed chances of a Bank of Canada interest rate hike next week and anxious about NAFTA.
"The President of Mexico (Enrique Pena Nieto) has been very clear: Mexico will never pay for this wall", Economy Minister Ildefonso Guajardo wrote on Twitter after a day of meetings in Washington.
A string of calming comments from Donald Trump about NAFTA has trade proponents across the continent breathing some relief that the USA president's trigger finger may not be about to blow up the deal after all. "They have an election coming up fairly shortly".
The question now is whether the president will decide to blow up NAFTA (or at least try - the legal mechanisms for withdrawal are uncertain and Congress may block a US exit).
In the newspaper interview, Trump also renewed a threat made during his 2016 presidential run: "If we don't make the right deal, I will terminate NAFTA". Those trends could offset some of the negative consequences from the loss of NAFTA trade, he said.
General Motors Co shares fell 2.4 percent. The U.S.is proposing in NAFTA talks to blow up that system, but the Canadians argue the U.S. still has a leg up.
Toyota Motor Corp.'s manufacturing plants for its popular Tundra trucks in the United States and in Mexico are operating at capacity and could face a similar decision about where to expand, Wood said.
Such an announcement by Trump would trigger a six-month countdown to the U.S. exit from NAFTA. Observers still view a US withdrawal notice as a potential bargaining ploy at some point. "Most likely the Canadians are reacting to the President's negotiating posture".
Freeland said on Thursday that Canada had come up with some creative ideas in a bid to unblock the talks. The talks are scheduled to wrap up by the end of March.
Yet, as Foreign Affairs Minister Chrystia Freeland made clear at the cabinet retreat in London, Ont., on Thursday, Canada's position has softened. "We make a good deal on NAFTA, and, say, I'm going to take a small percentage of that money and it's going toward the wall".
Separately, Canada launched a wide-ranging trade complaint against the United States, the World Trade Organization said on Wednesday, in a dispute that Washington said would damage Canada's own interests and play into China's hands.