There have also been numerous calls in the U.S. to include Canada. In a joint letter dated Monday, three major U.S. business groups -- the U.S. Chamber of Commerce, the Business Roundtable and the National Association of Manufacturers -- said it would be “unacceptable to sideline Canada,” the top buyer of U.S. goods. Prominent members of Congress have also said that Canada should be part of any new North American trade agreement.

“I think that if all three countries are in and all signed up, there’s a much higher likelihood this gets passed,” Bruce Heyman, a former U.S. ambassador to Canada under Barack Obama, said Tuesday on BNN Bloomberg television. There’s no sign a Mexico-only deal can be passed by Congress, he said, while shrugging off the significance of Scalise’s statement. “I think Steve Scalise is carrying water for USTR,” he said.

Panels, Tariffs

Canadian officials are warning that they’re prepared to see the next deadline pass if they don’t get an agreement they can live with, according to two people familiar with the talks. The Canadians need effective dispute settlement provisions in anti-dumping cases, and certainty to avoid misuse of national security investigations, under which Trump has applied tariffs, one of the people said.

Sticking points in talks include dairy, where the U.S., facing a supply glut, is seeking a bigger cut of Canada’s protected market. In exchange, Canada is hoping to preserve some form of anti-dumping panels contained in Chapter 19 of the North American Free Trade Agreement, and an exemption for Canadian cultural industries.

Other American demands include longer intellectual property and pharmaceutical patent protection and a higher threshold for duty-free shipments across the U.S.-Canada border, none of which the Canadians have signaled are deal-breakers.

It’s unclear what will happen if it becomes impossible to publish text of a deal by Sept. 30. The countries could extend talks, but that means Mexico’s president-elect, Andres Manuel Lopez Obrador -- who takes office Dec. 1 -- will have to be the one to sign the new agreement.

‘Always Tough’

Trump could try to proceed with Mexico only, but will face blowback from Congress, and the actual U.S.-Mexico agreement would probably require further changes, Hillman said, because it’s written in a way -- for example, a requirement that 75 percent of auto content be sourced within the trade pact’s member nations -- that appears to presume Canadian involvement. “You wouldn’t want to leave that number at 75 percent if Canada is not included,” because automakers couldn’t meet it, she added.

Trump, meanwhile, took aim at the Canadians again on Tuesday. “Canada has taken advantage of our country for a long time,” he said. “They are in a position that is not a good position for Canada.”