Updated

President Jacques Chirac warned Thursday that France could respond with nuclear weapons against any state-sponsored terrorist attack, broadening the terms of French deterrence to adapt to new threats.

The warning came as France works with other Western nations to ensure that Iran does not become a nuclear power, but officials and experts said Chirac's comments were not aimed specifically at Iran.

"Nuclear deterrence ... is not aimed at dissuading fanatic terrorists," Chirac said in a speech delivered at a nuclear submarine base in western France.

"Leaders of states who would use terrorist means against us, just like anyone who would envisage using, in one way or another, arms of mass destruction, must understand that they would expose themselves to a firm and fitting response from us," he said. "This response could be conventional. It could also be of another nature."

France's nuclear arsenal is considered a purely dissuasive means to protect the nation's vital interests and is not intended for regular combat.

However, in his speech, Chirac addressed new threats in the post-Cold War world, namely from regional powers. He did not explain what he meant by regional powers. But officials close to the president and experts said he was not singling out Iran, which alarmed Western nations last week by restarting nuclear activity after a 2 1/2-year freeze.

"In numerous countries, radical ideas are spreading, advocating a confrontation of civilizations," he said, adding "odious attacks" could escalate to "other yet more serious forms involving states."

He said nuclear warheads have been reduced on some missiles on France's four nuclear-armed submarines with the aim of targeting specific power centers rather than risk wholesale destruction in an enemy country.

"Against a regional power, our choice is not between inaction and destruction," Chirac said. "The flexibility and reactiveness of our strategic forces allow us to respond directly on the centers of power."

Chirac was speaking at a western base with the 110-strong crew manning The Vigilant — one of the four nuclear-armed vessels. Submarines carry 85 percent of French nuclear warheads.