PARIS, France (CNN) -- Iran's nuclear activity is a cover for a clandestine weapons program, French Foreign Minister Philippe Douste-Blazy has said in France's most direct attack on Tehran in the escalating international dispute.
Iran's chief nuclear negotiator immediately dismissed the charge, insisting that Iran did not "want to have the bomb."
Douste-Blazy's bold statement on Thursday appeared to reflect mounting exasperation and a tougher stance than European negotiators had previously maintained in their efforts to persuade Iran to suspend nuclear activities.
"No civilian nuclear program can explain the Iranian nuclear program. It is a clandestine military nuclear program," Douste-Blazy said on France-2 television.
"The international community has sent a very firm message in telling the Iranians to return to reason and suspend all nuclear activity and the enrichment and conversion of uranium, but they aren't listening to us."
Europe and the United States fear that Iran is using its nuclear energy program to build nuclear weapons, and the U.N. Security Council is to consider Iran's nuclear activities next month. Amid mounting tensions, Iran resumed small-scale uranium enrichment last week.
"Now it's up to the Security Council to say what it will do, what means it will use to stop, to manage, to halt this terrible crisis of nuclear proliferation caused by Iran," Douste-Blazy said.
While U.S. rhetoric towards Iran has been quite firm, European leaders have been more cautious. France, Britain and Germany have led European negotiations that have failed to persuade Iran to suspend parts of its nuclear program.
"People are clearly feeling somewhat frustrated that the Iranians have been given lots of opportunities they don't seem to want to take advantage of," said Richard Whitman of the Chatham House think tank in London.
He noted that the U.N.'s nuclear watchdog, the International Atomic Energy Agency, was unusually stern in reporting Iran to the Security Council earlier this month.
He said the French comments reflect "a sense of exasperation with the Iranian government. All of the doors that were open in terms of negotiations ... are gradually being closed by the Iranians."
The French Foreign Ministry insisted that Douste-Blazy's comments were in line with the European position on Iran.
"France shares the concerns of its European partners and the international community," spokeswoman Agnes Romatet-Espagne said. "The sensitive nuclear activities conducted now by Iran in terms of conversion and enrichment raise doubt about their peaceful and civilian nature."
In response to Douste-Blazy's comments, Iranian negotiator Ali Larijani said: "We want civilian nuclear energy, we don't want to have the bomb."
Speaking from Tehran on France-Inter radio, he said: "Concerning nuclear arms, we are a responsible country. ... We want to be in this camp" of countries that have nuclear energy technology, but no nuclear weapons, such as Brazil and Japan, he said.
In Washington, U.S. Secretary of State Condoleezza Rice said Wednesday that the United States would "walk a fine line" in seeking punitive international sanctions against Iran's Islamic government over its disputed nuclear program.
The next big test comes later this month, at talks in Moscow on moving Iran's enrichment program to Russia, which would allay fears that Iran might misuse the technology to make nuclear arms.
Tensions over Iran are likely to diminish if Tehran agrees to the Russian proposal -- and to balloon if it does not.
