NEW ORLEANS, Sept. 15 - President Bush called Thursday night for the rebuilding of the devastated Gulf Coast through the creation of a Gulf Opportunity Zone, a government enterprise that he said would provide help on taxes, housing, education and job training for the victims of Hurricane Katrina.

"The work that has begun in the Gulf Coast region will be one of the largest reconstruction efforts the world has ever seen," Mr. Bush said in remarks delivered in Jackson Square against the brightly lighted backdrop of St. Louis Cathedral, a symbol of the heart and soul of New Orleans for almost three centuries.

Mr. Bush delivered his speech, carried live by the major television networks, in the middle of the city's darkened French Quarter, where Army troops from the 82nd Airborne Division were on patrol. The Bush White House, well practiced in the art of presidential stagecraft, provided its own generators for the lighting and communications equipment that beamed Mr. Bush's remarks to the nation.

"And tonight I also offer this pledge of the American people: Throughout the area hit by the hurricane, we will do what it takes, we will stay as long as it takes to help citizens rebuild their communities and their lives," Mr. Bush said.

The mayor of New Orleans announced Thursday that residents and business owners could return to some parts of the city during daylight.

Mr. Bush ordered an immediate review of emergency plans for all cities, and said there was a need for greater federal authority and a broader role for armed forces in certain emergencies. He called for a federal government assessment of his administration's response to the storm and said that he would work with both parties in Congress in an investigation of what went wrong.

"This government will learn the lessons of Hurricane Katrina," Mr. Bush said.

The president did not, however, embrace calls for an independent commission to investigate the disaster.

White House officials viewed the speech as the culmination of a pivotal week in which Mr. Bush tried to turn around his image as a chief executive slow to respond to the greatest natural disaster in American history. The speech was meant to portray Mr. Bush as a forceful leader in control of the crisis and sympathetic to the people in the region.

"Tonight, so many victims of the hurricane and flood are far from home and friends and familiar things," Mr. Bush said. "You need to know that our whole nation cares about you, and in the journey ahead you are not alone. To all who carry a burden, I extend the deepest sympathy of our country."

Mr. Bush, dressed uncharacteristically in shirt-sleeves for a formal national address, said that the Gulf Opportunity Zone, encompassing Louisiana, Mississippi and Alabama, would provide tax incentives and loans for small businesses, including, he pointed out, minority-owned enterprises. Mr. Bush also said the federal government would provide evacuees with accounts of up to $5,000 that they could use for job training and education.

In addition, he asked Congress to pass what he called an Urban Homesteading Act, which would provide building sites on federal land through a lottery to low-income citizens, free of charge. In return, Mr. Bush said, residents would promise to build on the lots, with either a mortgage or help from a charitable organization like Habitat for Humanity.

Mr. Bush spoke after he was driven through empty, pitch-black streets, where members of the 82nd Airborne stood on corners in the darkness saluting the motorcade.

"I am speaking to you from the city of New Orleans, nearly empty, still partly under water and waiting for life and hope to return," Mr. Bush said from a lectern set up in the grass and hidden behind camouflage netting in Jackson Square.

In the aftermath of the storm, Mr. Bush said, "we have seen fellow citizens left stunned and uprooted searching for loved ones, and grieving for the dead and looking for meaning in a tragedy that seems so blind and random."

In his fourth trip to the region since the storm, Mr. Bush directly addressed the suffering of the largely poor, black evacuees at the New Orleans Superdome and convention center: "We have also witnessed the kind of desperation no citizen of this great and generous nation should ever have to know - fellow Americans calling out for food and water, vulnerable people left at the mercy of criminals who had no mercy and the bodies of the dead lying uncovered and untended in the street."

The president said state and local officials would have the primary role in planning for reconstruction, and in changing zoning laws and building codes. He listed many of the relief efforts now under way, including the registration of evacuees and retraining for workers.

Mr. Bush also tackled the tough issues of race and poverty that have been the source of enormous criticism and caused even Republicans to question the administration's commitment: "As all of us saw on television, there is also some deep, persistent poverty in this region as well. And that poverty has roots in a history of racial discrimination, which cut off generations from the opportunity of America. We have a duty to confront this poverty with bold action. So let us restore all that we have cherished from yesterday, and let us rise above the legacy of inequality."

Mr. Bush did not offer cost estimates for his proposals on Thursday night, but they were drawn from the kind of experiments - with "opportunity zones" and tax incentives - that Republicans have greatly preferred to huge federal spending efforts. The president seemed to try to balance a comprehensive government plan with an assurance that Washington would back away and allow Louisiana, Mississippi and Alabama - and the city of New Orleans - to decide how to rebuild.

"That is our vision of the future, in this city and beyond: We will not just rebuild, we will build higher and better," he promised.

Aside from the opportunity zone, Mr. Bush also proposed "worker recovery accounts" of up to $5,000 that evacuees could use for job training and education. The proposal sounds much like the kinds of accounts set up after the passage of the North America Free Trade Agreement in the early 1990's to help retrain workers displaced by foreign competition, a program that met with mixed reviews.

But in his speech, Mr. Bush also left some of the most controversial ideas unmentioned. His words seemed to imply that New Orleans neighborhoods would be rebuilt on the same sites that were flooded, rather than letting that land return to its original state, as wetlands that could provide a relief valve in the case of a future flood. Many of the most vulnerable neighborhoods were largely occupied by the city's poorest, and relocating those neighborhoods opened issues that one White House official said today "are not for us to deal with."

"Protecting a city that sits lower than the water around it is not easy," Mr. Bush said, "but it can and has been done."

He added: "And all who question the future of the Crescent City need to know: There is no way to imagine America without New Orleans, and this great city will rise again."

The federal government, Mr. Bush said, will undertake a "close partnership" with Mississippi and Louisiana, with New Orleans and other Gulf Coast cities so they can rebuild in a "sensible, well-planned way." He said the federal government will cover the majority of the costs of rebuilding the infrastructure in the disaster zone, from roads and bridges to schools and water systems.

The president said he expected the work to be done quickly, and that taxpayers would expect it to be performed "honestly and wisely." He promised to have a team of inspectors reviewing all expenditures.

But many Republicans predicted that the costs could run as high or higher than the war in Iraq, up to $200 billion, and noted that the White House had said $51.8 billion in emergency federal funds just approved by Congress, on top of an earlier $10 billion, would last for just a few weeks. Mr. Bush did not name a lead rebuilding official in the speech, as some White House officials are urging, and Scott McClellan, the White House press secretary, did not rule out the naming of such an official at a later date. Gen. Tommy Franks, who commanded forces in Afghanistan and Iraq, and John F. Welch Jr., the former chief executive of General Electric, are names often mentioned by Republicans as possibilities.

The president's proposal for an opportunity zone draws on more than a decade of federal experience with offering tax credits and other incentives for investment in economically depressed areas.

In 2002, the Bush administration selected New Orleans as a renewal community, eligible to share in billions of dollars worth of federal tax incentives intended to stimulate job growth and economic development. Last October, Gov. Kathleen Babineaux Blanco of Louisiana said the program had helped create jobs and must expand across the Delta.

Mr. Bush's proposal goes further. He would provide tax breaks, loans and loan guarantees to encourage businesses to invest in areas hit by the hurricane.

The Government Accountability Office, an investigative arm of Congress, said last year that federal agencies did not collect the data needed to assess the existing program or to show how the tax benefits had been used.

The president's comments were met with praise from local officials, including Ms. Blanco, who along with other local officials listened to Mr. Bush's speech from a bench in Jackson Square.

"Louisiana's people are strong, optimistic and determined to rebuild this great region, but we cannot do it without the resources of our nation and our government," she said. "I take the president at his word when he says those resources will be there when we need them."