Even though Louisiana state officials question his authority to issue the evacuation order, he said, "I don't care, I'm doing it. We have to get people out."

That meant people were once again bound to the city's Convention Center, where 25,000 people or more had huddled in desperate conditions for days. At St. Charles and Louisiana, about two dozen evacuees were patted down by U.S. Customs officials and placed on a bus for the Convention Center, where they were to be airlifted out of town. Told that some people were waiting as long as three hours at the Convention Center before being flown out, Nagin said that was a considerable improvement over the five days that it took some people to be evacuated last week.

"It's getting nasty and really smelly," Lucas Russ, 65, a retired school district employee, said as he prepared to board a bus with a bag of his belongings at St. Charles and Louisiana.

He said National Guardsmen told him that he had to leave and that he would receive no more food and water. National Guard officials denied this, and Nagin said that many evacuees were delirious, severely dehydrated, missing their medication and in need of immediate medical attention.

The mayor said the National Guard had asked him whether the handing out of sustenance provisions would encourage people to stay, but that his response was, "Do not harm anyone, do not allow anyone to starve, do not allow anyone to go without water and always treat everyone with respect."

That left officials with the question of how to strongly encourage holdouts to leave without outright forcing them unwillingly from their homes.

"I don't think we're ever going to do that," said Capt. Marlon Defillo, a spokesman for New Orleans police. "You're going to have people who are defiant not to leave. I don't think that's good PR."

President Bush intends to seek as much as $40 billion to cover the next phase of relief and recovery from Hurricane Katrina, congressional officials said Tuesday.

One week after the hurricane inflicted devastation of biblical proportions on the Gulf Coast, Senate Democratic leader Harry Reid, D-Nev., said the total tab for the federal government may top $150 billion. At the same time, senators in both parties said they suspect price gouging by oil companies in the storm's aftermath.