PARIS, FEB. 7 -- French President Francois Mitterrand, warning his countrymen that the Persian Gulf conflict is entering "a difficult phase," said tonight that a ground war to drive Iraqi forces out of Kuwait has become inevitable and will be launched before the month is out.

Mitterrand said the French people must brace themselves for a "cruel test" and many casualties expected in an allied land offensive, which he said "will start in the coming days, or perhaps a bit further along. In any case, it will take place this month." He said he did not expect the conflict to last into spring.

In Saudi Arabia, meanwhile, the commander of British forces in the gulf region told reporters that he also believes a land war "is inevitable," but U.S. commanders declined to join him in that assessment.

In Washington, Defense Secretary Richard B. Cheney remained noncommittal about the need for or timing of a ground offensive, telling a House committee just hours before he was to fly to Saudi Arabia that President Bush "is prepared to make {that decision} based on all the considerations he has to take into account as well as the recommendations we bring back."

Mitterrand, responding to questions from journalists in a televised interview, said he did not know if Iraq would unleash chemical weapons against allied ground forces, but he ruled out any retaliation in kind. "I say no to any use of chemical, biological or nuclear weapons," he said. "It is a recourse to barbarian methods that I reject."

Mitterrand said he profoundly regretted the fact that war had become the only way to liberate Kuwait, which he insisted would remain the principal goal of the 31-nation military coalition arrayed against Iraq -- a force that includes about 12,000 French troops. He said he believes there is little risk that gulf hostilities could grow into a wider conflict but added that "given Iraq's formidable military arsenal, if we had not acted now we would have found ourselves faced with conditions in three or four years that could have erupted into world war."

Once the gulf war is concluded, Mitterrand said, intensive diplomatic activity would mark "the beginning of peace." He said an international conference, or several of them, would be convened under the aegis of the United Nations to deal with fundamental sources of tension in the Middle East.

The main aims of these conferences, he said, would be to settle major border disputes and establish multinational security arrangements that would require large-scale disarmament and strict limits on weapons sales.

A proper resolution of the four-decade-old Israeli-Arab conflict, he said, will require the world community "to respond to Israel's legitimate security needs and the rightful aspirations of the Palestinian people."

Mitterrand did not discuss French efforts to sound out Iran on its current peace initiative and its role in any postwar security apparatus. Advisers to the president said he spoke by telephone for two hours Wednesday with Iranian President Ali Akbar Hashemi Rafsanjani, but they declined to discuss the substance of the conversation.

After nearly 15 years of close ties with Iraq, during which France supplied Saddam Hussein's regime with some of its most sophisticated weaponry, the French government has lately embarked on an intensive courtship of Iran. Diplomatic analysts here view this as an apparent attempt to establish a solid relationship with a gulf partner in a postwar era that France fears may be dominated by Washington's alliances with Saudi Arabia and Egypt.

At a cabinet meeting this week, Foreign Minister Roland Dumas was quoted by a government spokesman as telling the other ministers: "We must prepare ourselves for the idea that Iran will play a role in the final solution to the gulf crisis. Its geographic position, its importance and its interests make Iran an essential player in the process that will assure security and equilibrium in the Middle East."