President George Bush has promised long-term help to rebuild areas devastated by Hurricane Katrina.
President Bush says progress is being made in helping survivors
Speaking after touring the region, he said progress was being made. Aid is now reaching victims who had been stranded without food or medicine.
Evacuations are continuing. The president's visit comes amid bitter criticism that the administration's relief effort has been inadequate.
Mr Bush conceded that the initial response had not been acceptable.
The president spent Friday touring affected areas in Alabama and Mississippi, before taking a helicopter flight over New Orleans.
"This is a storm that requires immediate action, now," he said afterwards. "I want you to know that I'm not going to forget what I've seen.
"It's going to require the attention of this country for a long period of time."
He promised national help to rebuild the affected states and make New Orleans rise from its "darkest days".
The US Congress has approved a $10.5bn (£5.7bn) emergency aid package.
A military convoy of some 50 amphibious trucks carrying about 1,000 National Guard personnel managed to get long-awaited supplies to the New Orleans Convention Centre on Friday.
Up to 20,000 people had been stranded there for six days in conditions described by the BBC's Matt Frei as the most wretched he had seen anywhere - including crises in the Third World.
Food and water lines have now been set up, and under the supervision of armed guards, meals are being distributed.
"As fast as we can, we'll move them out," said Army Lieutenant General Russel Honore, in charge of the convoy.
People were overjoyed when they saw the convoy. But many still felt the help was coming far too late.
"They should have been here days ago," Michael Levy, 46, told AP news agency.
"We've been sleeping on the ground like rats. I say burn this whole city down."
Leroy Fouchea, 42, said two babies had died because of the sluggish rescue operation.
"They died right here, in America, waiting for food," he told Reuters news agency.
Meanwhile, some 1,300 patients have been rescued from the flooded Medical Centre of Louisiana, where they spent five days without electricity.
The evacuation of New Orleans is expected to take several days. Most of the flights will take refugees to Texas, which is providing emergency shelter for 75,000 survivors in Houston, Dallas and San Antonio.
Four days after the hurricane struck, the scale of the casualties is still not known.
However one senator from Louisiana, David Vitter, has predicted the death toll could climb above 10,000 in Louisiana alone.
Army engineers have said it will take anything from 36 to 80 days to pump the flood waters from the low-lying city.
Guardsmen who arrived in New Orleans on Friday were also said to be shocked at what they found - even though many of them have served in Iraq.
The situation was made worse by a lack of trust between the mainly poor, African-American population left behind in New Orleans and the predominately white police force, our correspondent adds.
Looting has swept the city. There have also been outbreaks of shootings and carjackings and reports of rapes.
Up to 60,000 people could still be stranded in the city, the US coastguard says.