WASHINGTON (AP) - A full recovery in New Orleans could take 25 years as homeowners, businesses and tourists are coaxed back to the city devastated by Hurricane Katrina, the Bush administration's Gulf Coast recovery coordinator said yesterday.

In an interview with The Associated Press, Don Powell said that much of the city's rebirth will hinge on factors he said were "out of our control," including restoring housing, ensuring safety and encouraging robust investment by the private sector.

"We kind of want it to happen overnight, or I do, but it's going to take some time," Powell said. "This could be five to 25 years for it all to fit into place."

Powell also said the Army Corps of Engineers now estimates it will cost an additional $5.9 billion to repair levees enough to fully protect and insure nearly 1.1 million residents of the greater New Orleans area.

That is in addition to the $3.5 billion the Bush administration has so far sought to bring the levees back to at least their pre-Katrina levels by June 1, the start of the 2006 hurricane season.

Powell said the Corps recently told him the administration must commit to spending as much as $5.9 billion more before it could fully certify the levees, as needed to issue flood maps that determine insurance rates and allow rebuilding to begin.

Powell said he does not know how many more federal dollars Washington will commit to the region, or whether some of the money will come from state and local governments. "We haven't decided what to ask for," Powell said.

But he said that decision and the release of new flood maps would likely happen in a "relatively short period of time - in a matter of days."

Over the next 60 days, Powell said, the Corps will be strengthening levees and building storm-proof pumping stations and flood gates to close certain parts of the City's canals in the event of a major storm.