Donald Trump took aim at Canada in the waning hours of his first 100 days in the Oval Office, blasting the dairy, timber, and energy industries as being unfair to American workers.

The U.S. President has repeatedly taken umbrage with the North American Free Trade Agreement, going so far as to threaten to tear it up before backing away from the stance ever so slightly after phone conversations with Canadian Prime Minister Justin Trudeau and Mexican President Enrique Peña Nieto, whose country carries a much larger trade surplus with the United States. Canada’s trade balance, by comparison, is relatively small, clocking in at $32.3-billion in 2016, and is entirely due to energy exports as Canada carries a small deficit on the services side.

While overtly critical of Canadian crude and vocal in his stance the United States should drill its way to energy independence, Trump has also sent a mixed message by greenlighting TransCanada Corp’s (TRP.TO) controversial Keystone XL pipeline. The pipeline, if approved at the state level, would increase Canadian export capacity by 510,000 barrels per day.

In a BNN interview on Friday, former Canadian Ambassador to the U.S. and current TransCanada board member Derek Burney said the approval was a positive development, but he needs to see the proof in the pudding.

“[Trump] has yet to demonstrate as a President that he can get anything done with a congress in which his party, supposedly, has a majority in both chambers. That’s the underlying issue,” Burney said. “We’ll just have to wait and see how it goes. I’m obviously optimistic that common sense will prevail.”

Burney said the U.S. should look to Canada as a reliable, stable source of oil instead of putting up nationalistic barriers to energy products.

“As the events in Venezuela continue to unfold, I think if I were an American, I would look north, rather than south, for a reliable supply of energy.”

While oil may continue to flow freely over the border, significant uncertainty surrounds the flow of milk and dairy products. A visit to Wisconsin, the dairy epicenter of the United States, put the Canadian industry in Trump’s sights earlier this month, as farmers in the state expressed outrage over a change to pricing practices of a milk byproduct called ultra-filtered milk. Canada did cut prices on the product, but its relatively small portion of the overall industry would do little to cut into Canada’s substantive dairy trade deficit with the United States.

While the dairy industry is by far the smallest in Trump’s sights, Burney said no matter the industry, Canada should not be so eager to offer appeasement in the form of renegotiating NAFTA.

“We can’t be saying to the Americans ‘Please renegotiate NAFTA.’ That’s not a position for Canada to take,” Burney said. “We need the three leaders [of] Canada, Mexico, and the United States to come to some consensus on what that negotiation is to be about before we can decide, in our own interests, whether it’s worth the candle. We don’t know that yet.”

Canadian officials have been extremely vocal in touting the benefit of Canada as an export destination for U.S. goods, repeatedly emphasizing that the Great White North is the primary customer for goods shipped from 35 states. Burney said that as a result, Parliament Hill shouldn’t cede to unequivocal demands from 1600 Pennsylvania Avenue.

“We have to keep our powder dry, we have to behave correctly, but we should not surrender to some kind of ‘gun at your head’ unilateral demand coming from the administration,” he said. “We’ve got to be very careful that we don’t give them the impression that we need this agreement more than they do.”

“The business community in the United States needs to start to speak up and put down some of the phony rhetoric that we’ve been hearing about NAFTA … it’s souring the mood about trade in America, and that’s not good for anyone.”