Preparations for possible war in the Persian Gulf intensified yesterday as the midnight (EST) U.N. deadline for Iraq's withdrawal from Kuwait passed with no sign of a diplomatic initiative that could bring about a peaceful resolution to the five-month-old crisis.

Following France's abandonment of a last-minute compromise proposal, U.N. Secretary General Javier Perez de Cuellar issued a final appeal to Iraqi President Saddam Hussein "to turn the course of events away from catastrophe."

Other members of the U.N. Security Council rejected as appeasement France's proposal on Monday to promise Saddam that an international conference would be held on the Palestinian question in exchange for withdrawal. "There is a fatal moment when one must act," French Prime Minister Michel Rocard said in Paris. "This moment has, alas, arrived after we have done everything to avoid it."

President Bush spent yesterday out of public view, meeting with his national security advisers. White House spokesman Marlin Fitzwater said the president was "ready to make the tough decisions ahead that are necessary" and described Bush as having "confidence in the correctness of our course and in the strength of our coalition."

He said the president had not made a formal decision to go to war, but he refused to respond to other questions about military planning or operations.

Asked whether U.S. officials believed Saddam might yet back down after the passage of the deadline, one official said, "That's in some people's minds, but no one who's making the decisions has much hope."

In a post-midnight statement that echoed its previous position, the White House said: "Jan. 15 was a day for Iraq to withdraw from Kuwait. It was not a deadline for U.N. action. The choice for peace remains with Saddam Hussein."

Baghdad radio reported that Saddam visited troops in Kuwait and urged them to be ready for war. "There will be no compromise on the nation's rights," he was quoted as saying.

At government-organized demonstrations, hundreds of thousands of Iraqis angrily denounced the United States and the multinational coalition aligned against Baghdad. "Kuwait is ours," they chanted.

Elsewhere in the Persian Gulf, a U.S. Marine air wing was in a heightened state of readiness, and the planes were being fitted with their combat load of bombs and missiles, according to a pool dispatch from the region.

In the United States, most major oil companies said they were restricting the amount of fuel wholesale customers can buy in response to indications that some distributors are hoarding petroleum as a hedge against war.

Law enforcement authorities issued new warnings about potential terrorism. The FBI announced three new counter-terrorism steps, including a "domestic threat warning" to 16,000 U.S. law enforcement agencies advising them to inform the nearest FBI office of any terrorist threats; notification of state authorities of possible targets identified through a new FBI "infrastructure" survey; and interviews with 3,000 Iraqis in this country whose visas have expired to determine why they are still here.

"The most likely targets are abroad, but we cannot discount the possibility that attempts will be made to strike here," Bill Baker, an FBI assistant director, said in a telephone interview.

"There is a lot of intelligence that . . . there will be an effort by a number of different terrorist organizations if hostilities occur," a senior Justice Department official said in a briefing for reporters.

The FBI's list of potential targets in the United States includes such sites as military bases, power plants, reservoirs, landmarks and transportation facilities. Airline industry officials said that passengers on all flights will face more hand-searches of luggage and that curbside check-in may be ended. The airline officials warned travelers not to let anyone else touch their bags, not to carry items for anyone else and to report unattended luggage to a security office.

As Bush met with his advisers, Lafayette Park and the sidewalks and streets in front of the White House filled with demonstrators -- pacifists, political radicals and fearful citizens -- who came to protest what they believed was the administration's rush to war. With prayers and banners and the beating of drums, they tried to persuade the president to change course.

Across the country, similar protests and vigils were held, with dozens arrested in Chicago and New York. In San Francisco, police arrested more than 400 anti-war demonstrators after a crowd estimated at between 3,000 and 10,000 -- some zipped into body bags -- tried to block the entrance to the Federal Building. Fifty others were arrested for blocking traffic on the Oakland Bay Bridge.

Prayer meetings were held in a number of cities, while teach-ins were conducted at a number of universities. As the prospects for peace dwindled, the children's television host, "Mr. Rogers," taped messages aimed at helping children deal with the possibility of war.

After a 90-minute national security meeting at the White House yesterday morning, Defense Secretary Richard B. Cheney met separately with Republican and Democratic senators at the Capitol.

"The president has instructed me to deploy the force and to prepare various kinds of plans," Cheney told reporters. "But he has not yet instructed me to carry out those plans."

Senators who attended the closed-door briefings said that Cheney had expressed satisfaction in the military chain-of-command in the gulf, a problem that has been a continuing source of discussion among U.S. military officers and allied governments.

"Everybody said they're ready and they've got a clear chain of command," Sen. Barbara A. Mikulski (D-Md.) said.

The senators reflected the darkening mood here and across the country. "There was a real feeling of dejection, resignation," Sen. Tom Harkin (D-Iowa) said. Harkin was one of the strongest opponents of the congressional resolution authorizing Bush to launch a war against Iraq.

Drawn by the spring-like weather, Bush began yesterday with a short walk on the south lawn of the White House. He also telephoned Edmond L. Browning, the presiding bishop of the Episcopal Church and one of the leaders of Monday night's prayer service at the Washington Cathedral, and Senate Chaplain Richard C. Halverson. Fitzwater said Bush told them "that he had been praying for peace during these troubled times" and asked the two men to pray for the country.

Fitzwater said the United States believed the search for peace "can or should continue as long as possible," but also issued another denunciation of Saddam's actions in the gulf.

"Has he violated all international norms and laws?" Fitzwater asked rhetorically. "Has he violated all standards of human rights? Has he murdered and killed the people of {Kuwait}? Has he raped and pillaged the land and all the resources of Kuwait?"

The coalition, Fitzwater added, should offer Saddam no reward for such actions. "You don't make an international hero or a peacemaker out of a man who has murdered and raped another country," he said.

Staff writers Helen Dewar, Al Kamen, Sharon LaFraniere, Don Phillips and Mark Potts contributed to this report.