The total evacuation of New Orleans is under way as conditions in the city battered by Hurricane Katrina worsen.
Buses have been taking the most vulnerable away to the Louisiana state capital - others are going to Texas.
Most of New Orleans is under water and many people have spent days on rooftops waiting to be rescued. Hundreds or even thousands are feared to have drowned.
President Bush acknowledged there is "frustration" at the pace of relief efforts, but called for patience.
He said boats and helicopters were on their way to the disaster area, as part of one of the biggest relief operations ever mounted in the United States.
In his interview with ABC television, he also condemned the wave of looting sweeping New Orleans.
"I think there ought to be zero tolerance of people breaking the law during an emergency such as this," he said.
Heat and stench
New Orleans Mayor Ray Nagin ordered the total evacuation of the city on Wednesday. He has said it will be months before people can return.
The tens of thousands of people who are still there are desperate to leave, the BBC's Alistair Leithead reports from New Orleans.
There is no electricity in the city, and people who have lost everything are struggling to find food and clean water.
Mayor Nagin said that between 50,000 and 100,000 people were still to be evacuated from the city. They were thought to include:
- At least 20,000 people who took refuge in the city's Superdome stadium
- 10,000 people - patients, staff and refugees - from nine city hospitals
- At least 7,600 prison inmates
Those in the Superdome stadium - where a refuge from Hurricane Katrina was set up - are living in appalling conditions.
The heat, humidity and sanitary conditions there are reported to be unbearable, and people are crowding onto the stadium's concourse to avoid the stench.
They are being taken in buses 560km (350 miles) to Houston's Astrodome stadium, where beds and blankets for up to 25,000 people have been set up.
Floodwaters in the city have stopped rising, but the army's Corps of Engineers said it would still take a while to drain the city.
They were planning to use Chinook helicopters to drop huge seven-ton sandbags into gaps in the failed floodwalls supposed to protect New Orleans from the Mississippi river and Lake Pontchartrain.
President George Bush flew over the devastated areas on Wednesday and said it would take years for the affected states to recover.
He vowed his cabinet would take over the aid operation for "one of the worst natural disasters" the US had seen.
An extra 10,000 troops are being sent to the worst-hit areas in Louisiana and Mississippi.
This will bring to 21,000 the total number of troops in areas hit by the hurricane, which include Alabama and Florida.
But hundreds of soldiers and police have been diverted from rescue work to law enforcement duties, amid reports that heavily-armed gangs are ransacking the city.
"They are starting to get closer to heavily populated areas - hotels, hospitals, and we're going to stop it right now," Mayor Nagin said in a statement to AP.
Looters were said to be threatening hospitals and nursing homes which still had food supplies, forcing staff and patients to seek help from the security forces.
"It's really difficult because my opinion of the looting is it started with people running out of food, and you can't really argue with that too much," Mr Nagin said.
"Then it escalated to this kind of mass chaos."
The government has declared a public health emergency along the whole of the Gulf coast to speed up the delivery of food, water and fuel to the region.
Officials in Mississippi state, to the east of Louisiana, have warned the death toll is likely to climb above the current 110.
The state's Harrison County bore the brunt of Hurricane Katrina as it slammed into Biloxi and Gulfport before heading inland.
Democratic senator Frank Lautenberg has accused the Bush administration of taking too long to respond.
"We are watching this devastation unfold on our televisions for days and you have to ask: where is the federal government?" the Reuters news agency quotes him as saying.
"We should have had a significant amount of troops and supplies there on the ground Monday."
Anger has also been reported among some of the poorer people hit hard by the hurricane.
"Many people didn't have the financial means to get out," Alan LeBreton, a Biloxi resident told Reuters news agency.
"That's a crime and people are angry about it," he said.