Former presidents George Bush Snr and Bill Clinton are expected to head the fund-raising campaign after the huricane Katrina slams US Gulf Coast.

By asking the two to team up once more, the White House hopes for a generous response worldwide and donations of hundreds of millions of dollars.

More than $82m has been raised so far, according to the Washington-based Chronicle of Philanthropy, which monitors charitable giving.

The funds are destined for organisations such as the Red Cross and he Salvation Army, who are embarking on a relief operation of unprecedented scale.

US President George W. Bush appeared twice on television. On ABC's "Good Morning America" he acknowledged the victims' anxiety and their sense of urgency, but promised "there's a lot of help coming," and he asked his critics to "not play politics."

"I hope people don't play politics during this period of time," Bush said. "This is a natural disaster, the likes of which our country may have never seen before."

And he urged motorists to "be prudent" in buying gas. "Don't buy gas if you don't need it," he said.

Source: Xinhua/agencies