Paris ? President Nicolas Sarkozy said Friday that he will cut France’s nuclear arsenal to fewer than 300 warheads, seeking to balance the defense of the nation – he mentioned the threat from Iran – against budgetary and strategic considerations.

In his first major speech as president on the French deterrent, Sarkozy also urged the United States and China to commit fully to a treaty banning tests of nuclear weapons.

In addition, Sarkozy shifted somewhat from the nuclear doctrine of his predecessor, Jacques Chirac, by being slightly more ambiguous about the circumstances that might lead France to employ its nuclear weapons.

Sarkozy’s decision to reveal the rough size of France’s arsenal – the Defense Ministry said the exact number of warheads is still secret – appeared aimed at prodding other nuclear powers to be equally transparent.

Many of France’s nuclear weapons are carried aboard submarines, with the rest on warplanes. Sarkozy said the airborne component would be cut by one-third, specifying that that included nuclear weapons, missiles and planes.

“After this reduction, our arsenal will include fewer than 300 nuclear warheads,” he said. “That is half the maximum number of warheads that we had during the Cold War.”

He also said none of France’s weapons is targeted at any nation.

France’s airborne nuclear weapons are carried by three air force squadrons of Mirage 2000N and another navy flotilla of upgraded Super Etendard jets. They are all to be replaced by high-tech Rafale jets, in air force and navy versions.

French defense expert Francois Heisbourg said the air fleet modernization allowed the size of the nuclear arsenal to be trimmed.

“When you have better planes taking over for older planes, you can afford to reduce the numbers,” said Heisbourg, special adviser to the Paris-based Foundation for Strategic Research think-tank.

“That doesn’t make us virtuous guys in itself, although of course it’s nicer to say the numbers are going down than the numbers are going up. What does make us more virtuous than we were before is by saying ‘By the way, that means we’re going to have 300.’ And that meaning is, ‘Oh by the way, dear Chinese friends, you better tell us how many you’ve got.”‘