Emmanuel Macron has announced France will increase its nuclear arsenal - claiming that France needs to be "feared" on the world stage.
The French President will also allow temporary deployment of its nuclear-armed aircraft to allied countries for the first time ever.
The move is part of a new strategy aimed at strengthening Europe's independence amid heightened geopolitical tension, but has been condemned by disarmament campaigners.
"To be free, one needs to be feared," Macron said at a military base at Ile Longue on Monday.
The base, in northwestern France, hosts the country's ballistic missile submarines.
Macron said the new posture could "provide for the temporary deployment of elements of our strategic air forces to allied countries", but insisted decision making regarding deployment would remain solely with France.
Since Brexit,the country has been the only nuclear power in the European Union.
It is understood his speech was planned long before the recent outbreak of war in Iran.
Britain, Germany, Poland, the Netherlands, Belgium, Greece, Sweden and Denmark are currently locked in talks about deterrence, Macron added.
France will also allow European partners to join in deterrence exercises, which has been welcomed across the continent.
In a joint statement, Macron and German Chancellor Friedrich Merz said the two countries would deepen integration in deterrence starting this year, "including German conventional participation in French nuclear exercises and joint visits to strategic sites".
In a letter to Dutch politicians, defence minister Dilan Yesilgoz-Zegerius and foreign minister Tom Berendsen said the Netherlands was in strategic talks with France on nuclear deterrence as "a supplement to, and not a replacement for, NATO's collective defence and nuclear deterrence capabilities".
Polish Prime Minister Donald Tusk wrote on X that "we are arming up together with our friends so that our enemies will never dare to attack us".
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France is increasing its number of warheads for the first time in 34 years.
They currently sit at below 300, however Mr Macron did not say how many more his country would maintain.
"I have decided to increase the numbers of warheads of our arsenal," Macron said.
"My responsibility is to ensure that our deterrence maintains - and will maintain in the future - its assured destructive power.
"If we had to use our arsenal, no state, however powerful, could shield itself from it, and no state, however vast, would recover from it," Macron said.
He did, however, rule out the possibility of German Air Force planes being used to carry French nuclear bombs - an idea floated by Merz last month.
European leaders have voiced growing doubts about American commitments to help defend Europe since President Donald Trump took office last year.
France and Britain have since adopted a joint declaration in July that allows both nations' nuclear forces, while independent, to be "coordinated".
The move has prompted fury from The International Campaign to Abolish Nuclear Weapons, which won the Nobel Peace Prize in 2017.
The group's executive director, Melissa Parke, said: "This announcement from French President Macron is a direct threat to the peace and security of the region, and the world.
"France already spent $6bn on its nuclear weapons in 2024 and it is unclear how much this unexpected increase will add to that exorbitant sum.
"This is not progress, it's a nuclear arms race that no one can afford."
(c) Sky News 2026: Macron says France must be 'feared' as he announces increase in nuclear arsenal
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