"We must explore all diplomatic possibilities," Jacques Chirac said at a press conference in Cairo where he arrived for a two-day visit on Wednesday.
Hosni Mubarak, his Egyptian counterpart, expressed the same view as Chirac and also advised against the use of military force.
"This question must be resolved through diplomatic and political means, distancing military operations which would have dangerous repercussions in the region," Mubarak said after meeting with the French president.
During his visit, Chirac is expected to discuss the Israeli-Palestinian conflict and Iran's nuclear ambitions with Mubarak.
Resumption of talks
The Iranian leaders "must understand that, for the international community, the prospect of a militarily nuclearised Iran is unacceptable," Chirac said in an interview to Al-Ahram, Egypt's state-owned daily, blished on Wednesday.
The French president, however, insisted that the doors remained open for a resumption of talks as soon as Iran went along with the requests of the International Atomic Energy Agency (IAEA) and the UN Security Council.
He said: "More than ever, the choice is in the hands of the Iranian leaders."
Iran, suspected by the West of wanting to acquire the atomic bomb, has refused to suspend its uranium enrichment activities in spite of pressure by the big powers.
Egypt is calling for a diplomatic solution to the crisis, but is also worried by the fact that Israel refuses to sign the nuclear Non-Proliferation Treaty (NPT). Experts believe Israel has some 200 nuclear warheads.