A war of words between U.S. and Canadian officials has raised the risk of a blow-up in North America's signature trade deal. This week offered, perhaps, the first hint of a thaw.Driving the news: Canadian Prime Minister Mark Carney signaled a desire for stronger U.S. ties — a shift in tone relative to earlier this year, when he suggested integration had created "vulnerabilities.""Let's be absolutely clear: A 'Canada Strong' will help make America great again," Carney said Thursday at the Economic Club of New York, borrowing President Trump's slogan to pitch a deeper partnership on autos, aluminum and critical minerals.Acknowledging U.S.-Canadian tensions, Carney said: "We have always worked and eventually worked through [our differences], because we share values and our common interests run deep."Between the lines: Already fraught bilateral tensions have taken a more adversarial turn ahead of the mandatory USMCA review, which requires the three countries to decide by July 1 whether to extend the agreement for another 16 years.Deputy U.S. Trade Representative Rick Switzer said last month that there's "not a grown-up in Canada in charge." While Carney was in New York, U.S. officials announced formal USMCA renegotiation dates with Mexico — with no talks set yet with Canada.Canada has sought stronger trade ties with the rest of the world, a deliberate push to reduce dependence on the U.S. market as Trump ratcheted up tariffs.The big picture: Carney did not mention USMCA by name, though his call for a "Fortress North America" hinted at the deal's importance.Carney, a former two-time central banker, framed Canadian aluminum exports to the U.S. as "the energy equivalent of 10 Hoover Dams," arguing it made little sense to replicate that capacity domestically.Carney said that the North American market was "the best and most durable way to confront" intense global competition.The bottom line: USMCA has shielded the U.S. from the worst of its own trade policies, though U.S.-Canadian tensions raise the risk that buffer will disappear."It's still the case that 85% of our trade goes across tariff-free. ... Everyone benefits from that," Carney said.