President Bush on Saturday ordered the U.S. flag to be flown at half-staff for five days to honor victims of the Indian Ocean tsunami as a White House delegation prepared to visit devastated areas.

A day after he raised the U.S. tsunami aid contribution ten-fold to $350 million amid pressure from critics, Bush used his weekly radio address to emphasize the need for private relief donations to a region where giant waves killed nearly 127,000 people and left 5 million homeless.

“The carnage is of a scale that defies comprehension,” said Bush, who announced that $15 million of U.S. aid has now been disbursed to relief organizations in the area.

Secretary of State Colin Powell and the president’s brother, Florida Gov. Jeb Bush, were due to leave for the tsunami-devastated region on Sunday as part of a delegation assigned to assess the need for further U.S. assistance.

Bush created the delegation and dramatically increased the U.S. relief contribution after criticism over the size and scale of his initial response to the catastrophe that struck 13 countries from Malaysia to East Africa six days ago.

Critics have noted that the government authorized $13.6 billion in aid for hurricane-battered U.S. states, mainly Florida, before last November’s election.

An administration official who requested anonymity said on Saturday the $350 million contribution would come from the government’s main disaster and famine assistance account.

The account, managed by the U.S. Agency for International Development, received $384.9 million in funding for relief projects for the current fiscal year.

Japan eclipsed the U.S. contribution on Saturday by pledging $500 million in aid.

The United States sees itself as leader of an international coalition including Japan, India and Australia that has pledged about $900 million in relief, or nearly half the $1.9 billion in contributions from country donors and official sources such as the World Bank.

In a White House proclamation issued in Crawford, Texas, where Bush is vacationing on his ranch, the president ordered the flag to be flown at half-staff from Monday to Friday next week at all U.S. public facilities and military installations, including embassies and naval vessels.

He said the gesture was meant as a mark of respect for tsunami victims.

Bush said Americans were making important private donations to the relief effort but urged further contributions through the Web site of the federal government’s volunteer program, USA Freedom Corps, at

“Donor and fund-raiser alike represent the best of our country and offer an example to the world,” he said.