Jakarta, Indonesia ? World leaders opened an emergency summit with a moment of silence for the tens of thousands of tsunami victims today, a day after a new round of competing donations saw pledges move well past $3 billion.

U.S. Secretary-General Kofi Annan told the gathering that his organization continued to estimate that the final death toll would surpass 150,000 across southern Asia and parts of Africa from the giant waves spawned by a powerful earthquake off Indonesia’s northwest coast Dec. 26.

“Although we were powerless to stop the tsunami, together we have the power to stop those next waves,” Annan said, launching an appeal for an addition $1.7 billion in disaster relief.

On Wednesday, Secretary of State Colin Powell and other summit participants got firsthand looks at the apocalyptic landscapes carved out by south Asia’s tsunami.

Powell, a battle-hardened veteran of the Vietnam War, was aghast at the devastation on Indonesia’s Sumatra island. “I’ve never seen anything like this,” he said.

India has politely turned down the unprecedented offers of money and military might, but many Indonesians appeared to be putting pride aside: During Powell’s visit, survivors expressed gratitude for American aid.

“Thank God he’s come. Thank God,” said Mohamed Bachid Madjid, peering from a bridge into the Aceh River, where two bloated corpses floated among the flotsam.

Pledges growing

The meeting came just hours after some nations increased their pledges. Australia promised $810 million — the largest so far — topping a $674 million German aid package.

The fresh outpouring of generosity appeared at times to be almost like a bidding war and raised questions about whether rich nations were using tragedy to jockey for influence on the world stage and with hardest-hit Indonesia, which has a wealth of natural resources.

Louis Michel, the European Commissioner for development and humanitarian aid, urged donors not to engage in one-upsmanship. “We have to be careful and not participate in a beauty contest where we are competing to give higher figures,” he said.

But U.N. humanitarian chief Jan Egeland, the man who riled Washington by complaining that wealthy nations were often “stingy,” said Tuesday: “I’d rather see competitive compassion than no compassion.”

Michel also said too many countries were making pledges that may not be honored.

A little over a year ago, donors promised Iran more than $1 billion in relief after an earthquake killed 26,000 people there. Iranian officials say only $17.5 million has been sent.

The twin pledges Wednesday by Australia and Germany pushed the total relief sum above $3 billion for the 11 countries hit by killer waves whipped up by a massive earthquake on Dec. 26.

Egeland, at the United Nations, called the two countries’ pledges “phenomenal” and said the offers were so large that his staff members had to ask donors to repeat what they said to make sure they heard the number of zeroes correctly.

In the early days of the disaster, Australia pledged $46 million. The country increased that pledge by another $764 million Wednesday, bringing its overall commitment to $810 million, officials said. Most of the pledge is for neighboring Indonesia.

“Out of the appalling tragedy of the tsunami has emerged an opportunity to build a new future,” Australian Prime Minister John Howard said. Rocky ties between Australia and Indonesia have improved steadily since the nations came together in the aftermath of the 2002 Bali nightclub bombings that killed 202 people, including 88 Australians.

The United States was the first to raise the stakes dramatically in the aid race by pledging $350 million on Friday; it now lies fourth on the donor list and has sent in two aircraft carrier groups and thousands of troops. Japan last week promised a $500 million package.

Even impoverished North Korea has chipped in with a pledge of $150,000. Convicts in Malaysia were donating money earned doing prison work, and war-torn Afghanistan planned to send doctors.

Budgeting the funds

The donors’ conference was focusing on how best to allocate the billions in aid following a disaster that wiped out villages and infrastructure, left millions homeless and threatened with disease, and killed more than 139,000 people. Leaders also were to discuss a warning system to prevent massive death tolls from future tsunamis.

The World Health Organization said it urgently needs $60 million to provide safe drinking water, sanitation, shelter, food, medical and other supplies to prevent disease outbreaks that would put another 150,000 people at “extreme risk” of dying. The United Nations announced that camps for up to 500,000 tsunami refugees will be built on Sumatra.

Touring overflowing hospitals in Banda Aceh on Wednesday, UNICEF director Carol Bellamy and WHO Director-General Dr. Lee Jong-wook saw the health problems close up: gangrenous wounds forcing surgeons to amputate limbs, scores of children with diarrhea, pneumonia cases caused by inhaling dirty water.

Powell was one of the first leaders to arrive in Indonesia ahead of the conference. From an altitude of a few hundred yards, he and his entourage saw not a tree or building standing along the coast. City block after city block in Banda Aceh had been swept clean. A large ship lay on its side, half submerged in water and mud.

“I cannot begin to imagine the horror that went through the families and all of the people who heard this noise coming and then had their lives snuffed out by this wave,” Powell said. “The power of the wave … to destroy everything in its path is amazing.”