Juppe, speaking on a television news channel in Paris, said that "experts are still discussing it, but in any case Iran is pursuing the development of nuclear arms, I don't think there is any doubt about that."
"The latest report by the International Atomic Energy Agency (IAEA) was quite clear on this point," Juppe said. "This is why France, without closing the path of negotiation and dialogue with Iran, wants tougher sanctions."
U.S. President Barack Obama put new economic sanctions against Iran into effect on December 31.
The French statement comes after Iran on January 2 test-fired a series of missiles near the Strait of Hormuz, which Iranian officials have previously threatened to close if Western powers pressed ahead with sanctions.
The U.S. and others have countered that Iran has no right to shut down the international waters, and U.S. officials have said they will not allow shipping to be disrupted in the strait.
compiled from agency reports