PARIS, Jan. 19 -- President Jacques Chirac said Thursday that France was prepared to launch a nuclear strike against any country that sponsors a terrorist attack against French interests. He said his country's nuclear arsenal had been reconfigured to include the ability to make a tactical strike in retaliation for terrorism.

"The leaders of states who would use terrorist means against us, as well as those who would envision using . . . weapons of mass destruction, must understand that they would lay themselves open to a firm and fitting response on our part," Chirac said during a visit to a nuclear submarine base in Brittany. "This response could be a conventional one. It could also be of a different kind."

The French president said his country had reduced the number of nuclear warheads on some missiles deployed on France's four nuclear submarines in order to target specific points rather than risk wide-scale destruction.

"Against a regional power, our choice is not between inaction and destruction," Chirac said, according to the text of his speech posted on the presidential Web site. "The flexibility and reaction of our strategic forces allow us to respond directly against the centers of power. . . . All of our nuclear forces have been configured in this spirit."

At the same time, he condemned "the temptation by certain countries to obtain nuclear capabilities in contravention of treaties."

Chirac's comments came during a flurry of diplomatic efforts by France, Britain, Germany and the United States to stop Iran from pursuing contested elements of its nuclear program. The International Atomic Energy Agency has called an emergency meeting for Feb. 2 to address Iran's recent decision to take steps toward advancing its uranium enrichment efforts.

"The timing doesn't look absolutely great," said Francois Heisbourg, a defense analyst who heads the Paris-based Foundation for Strategic Research. "It's not a speech you give if you're trying to convince people not to acquire nuclear weapons."

But Heisbourg said he believed Chirac's comments were aimed at a domestic audience rather than foreign powers. Political observers suggested that in the run-up to the 2007 presidential election, which Chirac is not expected to enter, the president is trying to protect a nuclear program that critics argue is too expensive.

According to an authoritative survey by the International Institute for Strategic Studies in London, France has 348 nuclear weapons, including 288 submarine-launched ballistic missiles, 50 air-launched cruise missiles and 10 bombs that could be dropped from airplanes.

Chirac said state-sponsored terrorism has replaced the threats of the Cold War era.

"In numerous countries, radical ideas are spreading, advocating a confrontation of civilizations," he said.

Chirac also said he has expanded the definition of "vital interests" -- which fall under the protection of the nuclear weapons program -- to include "strategic supplies" such as oil reserves and the "defense of allies."

Disarmament organizations called Chirac's threat to use nuclear weapons against states that sponsor terrorism irresponsible.

"Far from ridding France of nuclear weapons, the president is on the contrary considering the actual use of nuclear bombs," the anti-nuclear arms group Sortir du Nucleaire said in a statement.

"That's exactly the kind of message we should not be sending to the Iranians," said Ivan Oelrich, a nuclear physicist at the Washington-based Federation of American Scientists. "That nuclear weapons are a vital part of my defense and I'm going to use them in response to a terrorist attack."

On the same day Chirac delivered his speech, French diplomats were at the forefront of European efforts to persuade members of the IAEA board to consider action aimed at pressuring Iran to freeze its nuclear program.

U.S. and European Union officials say they believe Iran is attempting to develop the capability to enrich uranium for an atomic weapon under the cover of a nuclear energy program -- an allegation that Iranian officials vociferously deny.

While U.S. and E.U. officials are pushing IAEA members to refer Iran to the U.N. Security Council for possible sanctions, Russia and China are balking at taking such strong action. French Foreign Minister Philippe Douste-Blazy met Thursday with his Russian counterpart in Moscow.

"'We must simultaneously be united but also firm, to tell the Iranians to return to reason, to stop these dangerous nuclear activities and to let us negotiate," Douste-Blazy told reporters after talks with Russian Foreign Minister Sergei Lavrov.