Residents of storm-battered Louisiana should wait to return home until authorities give them the all-clear, a top disaster relief aide to US President George W. Bush warned Wednesday.

"We caution people not to come back in until they're sure that their parish has power, has water, sewer, and all those types of things it takes to survive," Federal Emergency Management Agency chief Dave Paulison said as Bush traveled here to see response efforts to Hurricane Gustav first hand.

"People are starting to move back into some of the parishes. We would caution people not to move back in until their parish president says it's safe to move back in," Paulison said aboard the presidential Air Force One airplane.

Bush, whose response to devastating Hurricane Katrina in 2005 drew harsh criticism, came here to survey damage from Gustav as hundreds of thousands who fled the storm began coming home.

"Now we're in the life protection and life-sustaining mode, making sure we have the tarps down there for the homes, we have water, food, cots, blankets, all those types of things we're going to need," said Paulison.

The FEMA chief said he was "pleased so far with everything" about the storm preparation and response but stressed: "We're going to have to stay on top of it."

"Based on what I saw in Katrina, where there was a lot of uncoordinated activity through the whole emergency management system, what I saw this time was a tremendous amount of coordination," said Paulison.

"Things are going to go wrong; there's no question about it, when you have a storm like this, things are going to go wrong. But when things happen, the whole federal team pulled together to make it happen," he said.

As an example, he noted that the Pentagon provided airplanes to help evacuate hospitals in storm-hit areas.

Paulison said he was confident that the US government could both fix the damage from Gustav and prepare for Tropical Storm Hanna, and noted he had already readied supplies and personnel.