Pledges of Help Grow Along With Problems

Egeland praised the response Tuesday, backtracking from his earlier remarks.

"The international assistance has been immediate and generous," Egeland said. "There are dozens of planes air-bound as we speak."

Still, Egeland called the situation "one of the most devastating natural disasters" and potentially one of the costliest, estimating that billions of dollars would be needed to rebuild. He warned that a "second wave" of the disaster could be deadlier than the first, as millions of people risk disease from contaminated drinking water.

Natsios said that the aid package had drained USAID's emergency relief fund, and it would have to ask the government for replenishments.

Relief officials are stunned by what they say is the unprecedented sweep of the destruction and the enormous amount of help needed. They say they are having to improvise and are struggling to coordinate myriad relief efforts among agencies, governments and private groups.

"This will be a massive effort, on all fronts," McGoldrick said. "This is groundbreaking. It is taking on proportions that no one could ever imagine."

The death toll is rising by the hour, and some remote areas remained out of reach, with untold devastation.

The priority within the next 72 hours, he said, is to get potable water and purification systems to survivors, as well as medicine and emergency shelter such as tents.

Agencies such as the U.N. are used to dealing with a couple of emergencies at a time, but nothing as widespread as the carnage in South Asia, McGoldrick said.

As devastated areas wait for international aid to arrive, volunteers are pulling together smaller, immediate relief efforts.

In Sri Lanka, a Canadian couple in Colombo organized an impromptu convoy to deliver food and medical supplies to the hard-hit town of Galle in the south.

Pamela and Jerry Porodo, two Canadians running a local property development company, said they offered their facilities, labor and fund-raising skills to the local Red Cross chapter, only to be blocked by bureaucracy.

So they joined dozens of volunteers who collected money, bought supplies and delivered them in a four-truck convoy themselves.

It took eight hours to struggle over 80 miles of washed-out roads, but their shipment was among the first to arrive.

Complaints about the slow pace of aid have been directed at governments, civic groups and international aid organizations.