OTTAWA — Canada’s plan to purchase 88 F-35 fighter jets, a deal valued at approximately 19 billion Canadian dollars, is facing renewed scrutiny following remarks by the United States ambassador that were widely interpreted here as linking defense cooperation to procurement decisions.

The contract, signed in June 2023 with Lockheed Martin, called for the acquisition of F-35A aircraft to replace Canada’s aging CF-18 fleet. The first 16 jets are already in production and scheduled for delivery beginning in 2026. But the remaining 72 aircraft — representing the bulk of the contract’s value — are now under formal review by the government of Prime Minister Mark Carney.

The reassessment follows comments by the U.S. ambassador to Canada, Pete Hoekstra, who suggested in a recent speech that decisions about fighter procurement could have implications for North American defense cooperation. Though he did not explicitly threaten to curtail joint operations, his remarks were perceived by many Canadian lawmakers as implying that failure to proceed with the American-made aircraft could complicate coordination under the North American Aerospace Defense Command, or NORAD.

Canadian officials responded cautiously but firmly. Defense Minister Bill Blair confirmed that Mr. Carney had directed a comprehensive review to determine whether the full F-35 purchase aligns with Canada’s long-term strategic and industrial interests.

“The first 16 aircraft will be delivered as planned,” Mr. Blair said. “But we have a responsibility to ensure that any further investment reflects both our security needs and the interests of Canadian workers.”

The review comes at a delicate moment in U.S.-Canada relations. President Donald Trump has in recent months imposed tariffs on certain Canadian goods and made pointed remarks about trade and economic policy. While defense cooperation between the two countries remains deeply institutionalized, political tensions have introduced new sensitivities into procurement decisions traditionally framed as technical and operational.

The F-35 has long been championed by the Royal Canadian Air Force, which argues that the fifth-generation stealth aircraft is essential to maintaining interoperability with the United States and other NATO allies. Canada joined the multinational development program in 2002 and has more than 100 domestic firms participating in the global supply chain.

Yet critics have questioned the extent of domestic industrial benefits. Although Canadian companies have secured contracts worth billions of dollars over the life of the program, final assembly and core technological control remain centered in the United States.

As Ottawa reconsiders its options, attention has turned to Sweden’s Saab, manufacturer of the Gripen fighter jet. The company has proposed assembling aircraft in Canada and transferring significant portions of production and maintenance work to Canadian facilities. Saab has publicly stated that such an arrangement could support thousands of domestic aerospace jobs.

For Mr. Carney, who campaigned on diversifying Canada’s economic relationships and strengthening domestic manufacturing capacity, the choice is both strategic and symbolic. Proceeding with the F-35 would reinforce Canada’s alignment with the United States and maintain seamless integration within NORAD operations. Pivoting toward Saab’s Gripen would signal a willingness to reduce reliance on American defense contractors and cultivate alternative partnerships.

Some defense analysts caution that the decision cannot be reduced to politics alone. The F-35 offers advanced sensor fusion and stealth capabilities that the Gripen, a fourth-generation platform, does not fully replicate. Maintaining a mixed fleet — retaining the initial F-35s while supplementing them with Gripens — has been discussed as a compromise. But operating two aircraft types would increase training, maintenance and infrastructure costs.

Still, public opinion appears to have shifted. Recent polling suggests a majority of Canadians support at least exploring alternatives to the F-35, particularly if domestic production is involved. Lawmakers across party lines have emphasized that procurement decisions must reflect not only military capability but also national sovereignty.

In Ottawa, the ambassador’s remarks are seen by some as a miscalculation. “Defense procurement is not just a commercial transaction,” one former senior security official said. “It’s about trust.”

American officials have sought to reassure Canadian counterparts that NORAD cooperation remains foundational to continental defense, regardless of specific equipment choices. The command structure, established during the Cold War, relies on close coordination between the two nations to monitor and defend North American airspace.

Strategically, Canada occupies a pivotal position, controlling vast Arctic airspace that would be traversed by any potential threat approaching from the north. That geographic reality ensures that cooperation will continue, analysts say, irrespective of the fighter model Ottawa selects.

For Lockheed Martin, Canada represents one of the largest export customers for the F-35 program. A decision to reduce or cancel the remaining order could have ripple effects, not only economically but symbolically, as other allied nations weigh long-term defense investments.

The coming months will determine whether Canada proceeds with the full purchase, adopts a mixed fleet or redirects its investment entirely. Officials have indicated that a decision must be made soon to avoid disruption to production timelines.

Beyond the technical comparisons and cost calculations, the debate underscores a broader shift in Canada’s strategic posture. As diplomatic friction with Washington intensifies, procurement decisions once treated as routine are being reexamined through a political lens.

What began as a straightforward modernization effort has evolved into a test of how Canada balances alliance commitments with domestic priorities — and how resilient cross-border defense ties remain amid strains at the political level.