In recent days, Canada and Portugal have expressed willingness to explore alternatives to the Lockheed Martin plane as President Donald Trump has sown doubt about the US commitment to the NATO alliance.

On Friday, Canadian Defense Minister Bill Blair said the country is actively looking at other fighter jets amid growing political momentum to scrap a $13 billion deal for 88 F-35s that was signed in 2023.

Canada has committed money for its first 16 planes, which are scheduled for delivery early next year. Blair indicated that after accepting that batch of F-35s, Canada could turn to European aircraft to replace its aging fleet of fighters.

“The prime minister has asked me to go and examine those things and have discussions with other sources, particularly where there may be opportunities to assemble those fighter jets in Canada,” he told the Canadian Broadcasting Corp., alluding to a Swedish proposal for Saab’s Gripen fighter.

A defense ministry spokesperson also told Bloomberg that the deal hasn’t been canceled, but Canada needs to “make sure that the contract in its current form is in the best interests of Canadians and the Canadian Armed Forces.”

The review of the F-35 deal comes has Trump has imposed tariffs on Canada and vowed to make the country the 51 state of the US, sparking outrage and boycotts of American products.

Meanwhile, Trump has long been skeptical of NATO and complained that member countries aren’t spending enough on defense. Despite allies boosting their outlays in recent years, he has signaled it’s not enough and threatened to not come to their aid.

“If they don’t pay, I’m not going to defend them. No, I’m not going to defend them,” he told reporters in the Oval Office last week.

In addition, Trump has threatened a trade war with Europe and alarmed allies there by warming up to Russia and halting US military aid to Ukraine, prompting the EU to embark on a massive military buildup in preparation for a world without a reliable US security shield.

The seismic developments rocking the trans-Atlantic alliance, which were underscored by Trump’s recent shouting match with Ukrainian President Volodymr Zelensky, are top of mind as another NATO ally weighs a separate purchase of fighter jets.

While Portugal’s air force has recommended buying F-35s, outgoing Defense Minister Nuno Melo told Público that the country can’t ignore the current geopolitical environment.

“The recent US stance in the context of NATO and the international geostrategic dimension, makes us think what are the best options, because the predictability of our allies is a factor to be reckoned with,” he said.

He added that “this ally of ours” could limit use as well as maintenance support and access to components that are needed to ensure the aircraft are operational “in all types of scenarios.”

“There are several options that must be considered, particularly in the context of European production,” Melo said, with the defense ministry later adding that Portugal isn’t ruling out the F-35.

Reluctance among foreign militaries to buy the F-35 comes on top of concerns that the Trump administration is looking to slash US defense spending. As the Pentagon’s most expensive acquisition program, the F-35 has been a perennial punching bag and has previously drawn Elon Musk’s scorn as being inferior to drones.

The White House and the Defense Department’s joint program office for the F-35 didn’t immediately respond to requests for comment.

A spokesperson for Lockheed Martin said the company values its partnership and history with the Portuguese Air Force and looks forward to continuing that partnership in the future.

“The F-35 is the most advanced, survivable and connected fighter aircraft in the world, enabling 21st Century Security and allied deterrence,” Lockheed said in a statement to Fortune. “Questions about foreign military sales of the F-35 are best addressed by the US government.”

Lockheed provided a similar comment about Canada’s F-35 review.

In a separate statement to the CBC, the company sought to dispel online misinformation that claims the F-35 has a “kill switch” that allows the US government to cripple the aircraft, saying “we deliver all system infrastructure and data required for all F-35 customers to sustain the aircraft.”

Still, an American promise is looking more doubtful as the US upends traditional geopolitics, according to Quantum Strategy’s David Roche, who told CNBC earlier this month that “NATO is dead” as Trump distances the US from long-time allies.

That makes Russia’s Vladimir Putin and China’s Xi Jinping the big winners, as they see confirmation of their views that democratic powers are on the decline, Roche explained.

“The big loser is actually the US, because nobody will trust a US treaty again,” he added, noting that a lot of so-called Global South countries will fall into China’s orbit as a result.