President Bush said Wednesday he is asking Congress for $950 million to support victims of last year's devastating tsunami (search) in the Indian Ocean, more than doubling the U.S. pledge.

The request, expected to go Congress in a few days for lawmakers' approval, would add $600 million to the current commitment of $350 million.

"We will use these resources to provide assistance and to work with the affected nations on rebuilding vital infrastructure that re-energizes economies and strengthens societies," Bush said in a statement.

Andrew Natsios (search), administrator of the U.S. Agency for International Development (search), said the humanitarian pledge would be the government's "most generous and extensive" ever, surpassing the aid sent to Central American nations after Hurricane Mitch in 1998.

The pledge would put the United States atop of the list of donors to the disaster, a turnaround after the early criticism that Bush responded to the Dec. 26 earthquake and tsunami too slowly and with too little money.

Australia has pledged $810 million, followed by Germany's $660 million, $624 million from the European Commission, and $540 million from Japan.

Part of the $950 million would replenish the $346 million already spent by USAID and the Pentagon in response to the disaster.

The money would pay for rebuilding infrastructure such as highways, bridges, schools and water distribution systems. It would help with housing construction and technical assistance to governments.

About $35 million would go to help develop an Indian Ocean early warning system that would alert citizens not only to earthquakes and tsunamis but to typhoons, and to improve the U.S. early warning system.

An undetermined amount of money could be found to defer some debt owed by countries in the tsunami zone if they request it, said Alan P. Larson, undersecretary of state for economic, business and agricultural affairs.

The request will be part the $80 billion being sought to cover continuing military costs in Iraq and Afghanistan.

Natsios stressed that it is important to coordinate with host countries to make sure the spending is well-coordinated and effective.

"It's going to be spent over a relatively short period of time and we have to have complete transparency," he said.

The disaster has killed at least 157,000 people and left millions more homeless, destitute and without loved ones.

In response, the U.S. military alone has spent $224 million, delivering 10 million pounds of food and 400,000 gallons of water, treating 2,500 sick and injured patients and providing other help, Deputy Defense Secretary Paul Wolfowitz said.

"We have achieved an enormous humanitarian success and have a large stake in making sure that success doesn't go to waste," Wolfowitz said.

The military still has 3,600 people in the region, most on ships that are supporting helicopter supply deliveries and on the hospital ship USNS Mercy. The Mercy is to remain even as the military continues to phase out its other relief activities in the region, Brig. Gen. John Allen said.

At the peak of the military's response, there were 16,000 personnel in the area.

Former Presidents George H.W. Bush and Clinton will visit affected countries on Feb. 19-21.