Amid angry local criticism of the Federal relief effort in South Florida, President Bush said today that he would send troops to help feed residents and rebuild the area after a hurricane that he said might be the worst natural disaster in the nation's history.
Pentagon officials said 2,000 to 5,000 troops were being flown from Fort Bragg in Fayetteville, N.C., along with portable kitchens, medical supplies, helicopters and bulldozers. A professional disaster-relief specialist characterized the move as welcome, though modest and tardy.
"The damage has created tragedy for millions of Floridians," Mr. Bush said, just before boarding Air Force One after a campaign swing through St. Louis, Cincinnati and Findlay, Ohio. "The damage is far more widespread than even we had feared. ' Bush Cancels Trips
Pentagon officials acknowledged that tonight's action was arranged within a matter of hours, after orders from the White House this afternoon, and Mr. Bush abruptly canceled a weekend trip to his home in Kennebunkport, Me., and a campaign swing through the West next week so that he could "monitor relief efforts."
The announcement came after local officials and disaster relief experts said that Federal efforts had been inadequate and often confused and that four days after Hurricane Andrew struck South Florida, uncounted thousands of residents still lacked food, water and shelter.
As the magnitude of the disaster sank in and the frustration level rose, Mr. Bush conferred with aides between campaign stops in the Midwest.
Florida, the nation's fourth most populous state, is considered crucial to Mr. Bush's re-election, and he had cut off a campaign swing in Connecticut on Monday to survey the immediate aftermath of the storm and announce several relief initiatives. But the Bush Administration had confined its relief effort to the scale appropriate for past disasters and had refrained from taking extraordinary measures.
Military officials were still arguing up to the moment Mr. Bush issued his mobilization order that such an effort would require several days to organize. They also said the Pentagon was hampered by legal restrictions from launching major operations within the country. Indeed, on Monday, Federal officials denied a request from Florida's Governor, Lawton Chiles, to supply an Army engineering battalion.
In a briefing tonight, Pentagon officials said the soldiers would be on the ground in South Florida by morning, and would be equipped with 20 mobile kitchens capable of feeding 6,000 people three meals a day.
The kitchens will be flown to the air base at Homestead, Fla., which was demolished when the hurricane struck South Florida early Monday with winds of 150 miles an hour. Security Force Planned
On Friday, medical, engineering, aviation and service support troops are scheduled to arrive to help with sanitation and to distribute supplies and provide electrical generators. Troops from an infantry and mechanized battalion are being sent for security.
Since Monday, South Dade County has resembled a war zone. Shattered buildings are everywhere, dazed people wander aimlessly in the streets, a black market in scarce food and water has sprung up, and heavily armed National Guard troops limit access to the storm-damaged zones at checkpoints.
Mr. Bush said he was mobilizing the military at the request of Governor Chiles, who had earlier said food distribution had become hopelessly tangled in bureaucracy and general confusion.
It was still unclear tonight whether the troops would tackle the big jobs of reconstructing roads and homes or rebuilding electric power grids. But it was certain that no Federal effort, however huge, could restore South Florida in a matter of days.
Emergency deliveries of food and water are still tangled in distibution problems, officials said earlier today.
"We've got 120,000 C-ration meals that are here somewhere, but we don't know where the hell they are," Governor Chiles said. "Right now, a truckload of food gets there, 200 people show up, 50 people get food and 150 people are angry. We've got to find a way to solve that."
At the same time, officials at the Army Corps of Engineers acknowledged that they were sitting on 2,000 rolls of plastic sheeting that could be used as emergency roofing, even though an estimated 250,000 people in Florida are now homeless. The reason: the Army is in the process of hiring private companies to install the sheeting, a job that may not actually get under way for several days.
Defense Department officials acknowledged that they have military units that can do the job, but said they are normally required by law to avoid competing with private business whenever possible. It was not clear whether the soldiers now heading for Florida would be authorized to do this job. Slow Start for Task Force
Meanwhile, a special task force proclaimed by the President to marshal all the resources of the Federal Government had got off to a slow start. So far it has only two members: Andrew H. Card Jr., the Secretary of Transportation, and Wallace Stickney, head of the Federal Emergency Management Agency. Secretary Card, given overall authority by Mr. Bush to supervise relief efforts, spent most of the day "assessing" local needs, officials said.
Maj. Gen. John Heldstab, director of military support under the Secretary of Defense, said Mr. Card had urged the President to take the action. "The assessment made by Secretary Card was that we just needed more," he said.
Experts in international relief efforts said the Government's early effort in South Florida, where damage estimates are double the combined toll of Hurricane Hugo and the earthquake in Northern California in 1989, were appropriate but overdue.
"It's a little more modest than I would have done," said Richard Walden, president of Operation USA, an international relief organization based in Los Angeles. "They could have had plans 36 hours ahead of time."
The Pentagon, which has become highly skilled in disaster relief in other parts of the world, had been only marginally involved here, providing air cargo planes, and equipment like portable electric generators and water purification systems. By contrast, the massive relief operations overseen by the Pentagon in southern Turkey involved building tent cities for hundreds of thousands of Kurdish refugees after the Persian Gulf war. Generators for Hospitals
Tonight at the Pentagon, General Heldstab said: "Clearly, I think when you go into a disaster situation, there are a series of things you need to do initially. The first is to provide food, water, shelter. You need to clean the place up so folks can move around; that's debris removal. And I think we'll be doing some of all of that."
The military is sending four 750-kilowatt electrical generators to help power hospitals or other buildings. General Heldstab said the military had been prepared to provide generators before today but that for some reason no request for such help had been made through official channels.
General Heldstab said the military was sending five search and rescue specialists. Only 15 percent of the area struck by the storm has been searched for victims, local officials say.
Three medical helicopters are being deployed to South Florida, and a supply barge from Guantanamo Naval Base in Cuba has set sail with $645,000 worth of food, beverages, pillows, eating utensils and other items.
While the Pentgon is sending some infantry troops to provide security, General Heldstab said it did not want to take on the job of law enforcement.
Photo: Hundreds of people waited in line five hours yesterday at a food and water distribution area near a shopping center in Homestead, Fla. (Keith Meyers/The New York Times) (pg. A1); Two people were killed and another injured as a small plane carrying aid to the victims of Hurricane Andrew crashed into the roof of a house in Miramar, near Miami. Firefighters hosed down the wreckage.