PARIS — European allies’ eyes turn toward France on Monday as President Emmanuel Macron is set to update French doctrine on the potential use of nuclear weapons, in a keynote speech from the military base hosting the country’s ballistic missile submarines.

Macron is expected to outline France’s strategy and spell out how French nuclear weapons fit into Europe’s security amid concerns raised on the continent by recurring tensions with U.S. President Donald Trump over Ukraine, Greenland and NATO.

The long-planned speech was maintained despite the growing conflict around Iran, because the current violence in the Middle East shows the importance of France’s power and independence to face down growing threats, according to a French official, speaking anonymously in line with the French presidency’s customary practices.

European leaders have voiced growing doubts about U.S. commitments to help defend Europe under the so-called nuclear umbrella, a policy long intended to ensure that allies — particularly NATO members — would be protected by American nuclear forces in the event of a threat.

France is the only nuclear power in the European Union. Macron’s office said the speech is expected to build on his 2020 address on nuclear deterrence, delivered before Russia’s full-scale invasion of Ukraine reshaped the security landscape in Europe.

No detail has been disclosed ahead of the speech.

Some European nations have already taken up an offer Macron made last year to discuss France’s nuclear deterrence and even associate European partners in nuclear exercises.

Earlier this month, German Chancellor Friedrich Merz said he’d had “initial talks” with Macron on the issue and had publicly theorized about German Air Force planes possibly being used to carry French nuclear bombs.

“We have to re-articulate nuclear deterrence,” Macron said at the Munich Security Council this month. He said France had had “a strategic dialogue” with Merz and with some other European leaders “in order to see how we can articulate our national doctrine, which is guaranteed and controlled by the Constitution, with special cooperation, common exercises and common security interests.”

France and Britain also adopted a joint declaration in July that allows both nations’ nuclear forces, while independent, to be “coordinated.” The U.K., no longer an EU member but a NATO ally, is the only other European country with a nuclear deterrent.

Macron has consistently insisted any decision to use France’s nuclear weapons would remain only in the hands of the French president.