The White House's top hurricane-relief adviser said Tuesday he has not decided whether the federal government should pay to make New Orleans' levees stronger than they were before Hurricane Katrina.

Donald Powell declined to say how long it would take before a decision is made.

Katrina, a Category 4 storm, surged through the city's levees at numerous points when it struck three months ago, killing more than 1,000 people.

Powell said he is gathering information from local and state officials and will eventually recommend to the Bush administration whether the levees should be strengthened to protect against more powerful Category 4 or Category 5 storms.

Gov. Kathleen Blanco and other Louisiana officials, as well as businesses and homeowners, have said the levees must be improved to protect against Category 5 storms if the New Orleans metropolitan area hopes to persuade people to return.

Such improvements would require federal funding. Early estimates run as high as $32 billion, and it would take up to 30 years to complete the work.

For now, the U.S. Army Corps of Engineers is rebuilding the levees for Category 3 storm protection — or as strong as they were supposed to be before Katrina.

Engineers have debated whether the levees were as sturdy as advertised. They have found evidence of design flaws and poor maintenance that left the flood-control structures much weaker in some spots than they were meant to be.

Powell met with Blanco at the Louisiana Capitol as part of a fact-finding tour of the Gulf Coast.