GEORGE W Bush saw at first hand last night the devastation wreaked by Hurricane Katrina and felt the backlash of criticism that he had done too little too late.

Asked how the richest country on Earth could not meet the needs of its people, the president said: "I am satisfied with the response. I am not satisfied with all the results."

He rejected suggestions that the US could not afford both the war in Iraq and the hurricane clean-up. "We'll do both.

We've got plenty of resources to do both."

But he told people who lost everything in the hurricane to seek aid from the Salvation Army.

Despite his appearance at the disaster area, the storm of criticism grew, with even Republicans in angry mood.

David Vitter, Louisiana senator, predicted the death toll would top 10,000 in his state alone.

Newt Gingrich, former House speaker, questioned how Homeland Security could plan for disasters when this was so chaotic.

Ray Nagin, mayor of New Orleans, was scathing of Mr Bush, warning "every day that we delay, people are dying and they're dying by the hundreds".

He said more than 50,000 survivors were still stranded on rooftops and in shelters.

In Biloxi, Mississippi, Mr Bush comforted Bronwynne Bassier, 23, who told him: "My son needs clothes."

Ms Bassier and her sister Kim, 21, escaped the storm but her house was in ruins."Sorry you're going through this, " Mr Bush said, hugging both women, and telling them they could get help from the Salvation Army.

But the Salvation Army warned it was running out of food and other supplies. Major George Hood, its spokesman, said in Jackson, Mississippi:

"We are running out of food, running out of supplies, and are finding it extremely difficult to find them."

The National Guard brought food, water and weapons to New Orleans as they churned through the floodwaters in a vast truck convoy with orders to retake the streets, put an end to looting, and bring relief to the suffering. "The cavalry is and will continue to arrive, " said Lieutenant General Steven Blum, of the National Guard.

Despite his optimism, anarchy and looting were still rife in the city, and army engineers warned it could take up to 80 days to clear away the city's floods.

Mr Bush was to sign a GBP6bn federal disaster relief order, but in the meantime he urged people to donate money to the Red Cross. Private donations to US charities helping the victims have risen to around GBP110m.

The crisis facing the thousands trapped in the area was highlighted by the daughter of a Scot caught up in the disaster. She said her mother had been forced to join in the looting to find food. Teresa Cherrie, 42, a nurse from Renfrew, is stuck in Baton Rouge. She and her partner, John Drysdale, 41, have been waiting for rescue on the roof of an apartment block.

They have been forced to loot supermarkets for food while trying to hide from gangs that roam the streets. Nicola Cherrie, 21, a dental nurse, said her mother said "she'd never been so starving in her whole life, she'd never seen so many guns, she'd never been so scared. She said they had a tin of ravioli and a packet of biscuits for their dinner."

Mr Nagin was scathing in criticism of Mr Bush and federal officials, saying: "They don't have a clue what's going on down here. They flew down here one time two days after the doggone event was over with TV cameras, AP reporters, all kind of goddamn - excuse my French everybody in America, but I am pissed.".

He added: "You know, God is looking down on all this, and if they are not doing everything in their power to save people, they are going to pay the price.

Because every day that we delay, people are dying and they're dying by the hundreds, I'm willing to bet you."

Mr Gingrich, on Homeland Security and Northern Command planning, warned that "if we can't respond faster than this to an event we saw coming across the Gulf for days, then why do we think we're prepared to respond to a nuclear or biological attack?"

He urged Mr Bush to call in Rudolph Giuliani, former New York mayor, to take charge of the White House relief efforts.

Mr Bush said in Biloxi: "The levees broke on Tuesday in New Orleans. On Wednesday and Thursday, we started evacuating people . . . I am satisfied with the response. I am not satisfied with all the results."

However, black members of Congress and black groups expressed anger, claiming the response was slow because those most affected are poor.

One person died and 10 were injured when a bus carrying them from the Superdrome overturned.