Though France and Britain are both nuclear powers, most European countries have relied primarily on the United States for deterring any potential adversaries — a decades-old pillar of transatlantic security. But Trump's rapprochement with Russia on the Ukraine war and his harsher posture towards traditional allies have rattled European governments, and some countries have expressed interest in how Paris could protect them by extending its nuclear umbrella.
"We are currently experiencing a period of geopolitical upheaval fraught with risk," Macron said in a speech delivered from a submarine base in Brittany, adding that a hardening of the French deterrence model was needed. Unveiling the update to France's nuclear doctrine, a once-per-term ritual for presidents, Macron promised more co-operation with European allies that have expressed interest.
Germany, but also Greece, Poland, the Netherlands, Belgium, Denmark and Sweden would be able to take part in French nuclear wargames.
"I believe I can say our partners are ready," Macron said.
Still, Macron gave no details on how the enhanced nuclear drive would be funded, while making clear decision-making on nuclear strikes will remain solely in the hands of the French president.
German Chancellor Friedrich Merz said in a joint statement with Macron that France and Germany had established a nuclear steering group to discuss deterrence issues and would start concrete cooperation this year.
That would include participation by conventional German forces in French nuclear exercises and joint visits to strategic sites, as well as the development of non-nuclear capabilities with France and other European partners.
Polish Prime Minister Donald Tusk said on X Poland was in talks "with France and a group of closest European allies on the programme of advanced nuclear deterrence".
"We are arming up together with our friends so that our enemies will never dare to attack us," he added.
The French leader said it would be possible to establish, under unspecified circumstances, strategic assets in other European countries that would be part of what he called a new "forward deterrence" doctrine. "Our strategic air forces could be spread deep into the European continent," Macron said, without giving more details.
Although the size of France's nuclear arsenal is based on a strategy of "strict sufficiency", the number of French warheads will be increased, Macron said.
France spends roughly 5.6 billion euros ($A8.53 billion) a year to maintain its stockpile of 290 submarine- and air-launched weapons — the world's fourth-largest arsenal. Britain has 225 nuclear warheads. Russia and the United States have more than 5,000 each.
Macron said close ties on nuclear deterrence will continue with Britain. He also said the current rethink of French nuclear doctrine has been done in total transparency with Washington, and was complementary to NATO's nuclear mission.
