PORT-AU-PRINCE, Haiti — For the first time since a catastrophic earthquake shuddered across Haiti last week, there were real signs of relief yesterday, with U.S. helicopters ferrying emergency supplies from an aircraft carrier off the coast and bulldozers taking to the streets of Port-au-Prince to shove through mountains of debris.

But there also were signs of the immense problems ahead: the stench of decaying bodies rising from neighborhoods; the sprawling tent cities springing up across the capital; the challenge of getting help to the victims in the face of the breathtaking scale of destruction and need.

U.S. officials made a concerted push yesterday to show support for the survivors of a disaster that may have left more than 100,000 people dead.

In Washington, President Obama met with his two immediate predecessors, George W. Bush and Bill Clinton, whom he has designated to lead a massive private fundraising effort for Haiti.

"These two leaders send an unmistakable message to the people of Haiti and the world," Obama said of the former presidents flanking him at the Rose Garden. "In a moment of need, the United States stands united."

Hours later, Secretary of State Hillary Clinton arrived in Haiti aboard a flight that carried an aid shipment. She is the highest-ranking U.S. official to visit the impoverished Caribbean nation since the magnitude 7.0 earthquake left the capital in ruins.

On a field near Port-au-Prince's airport with a view of the runway, small crowds of Haitians watched as U.S. military helicopters landed at the airport, a frenetic hive of activity as flights arrived carrying everything from forklifts and earth-moving equipment to food and medical aid, and search-and-rescue teams and crowds of civilians lined up for hours to catch charter flights out.

100,000 MAY BE DEAD

Haitian officials have said the death toll could exceed 100,000 and might reach twice that number.

Yesterday, the State Department confirmed the deaths of 15 U.S. citizens: a diplomat and 14 private individuals, according to The Associated Press.

The United Nations said that the body of Haiti mission chief Hedi Annabi had been found in the rubble of its Port-au-Prince headquarters, which collapsed in the earthquake.

U.N. Secretary-General Ban Ki-moon said the bodies of Annabi's deputy, Luiz Carlos da Costa, and the acting police commissioner, Doug Coates, had also been found.

Rescuers digging in the rubble still held out hope of finding survivors, despite the dwindling odds. U.S. officials said search-and-rescue operations would continue over the weekend, even as the focus was shifting to humanitarian relief.

The Pentagon reported that as of Friday night, 4,200 U.S. military personnel were supporting task force operations, within Haiti and from Navy and Coast Guard vessels offshore. An additional 6,300 military personnel were scheduled to arrive through the weekend.

In Port-au-Prince, Secretary of State Clinton met with Haitian President Rene Preval and other leaders to discuss the emergency response.

Clinton said she and Preval agreed to work closely on relief work and restoring basic services, such as telecommunications, electricity and transportation. She said the two would issue a joint statement tomorrow outlining what comes next.

In remarks directed to the Haitian people, Clinton said: "We are here at the invitation of your government to help you. As President Obama has said, we will be here today, tomorrow and for the time ahead."

Amid an atmosphere of desperation in Port-au-Prince, with reports of scattered looting and mob violence, Obama counseled patience as the international relief effort moves forward.

"There's going to be fear, anxiety, a sense of desperation in some areas," Obama said. But, he added, "we are going to be making slow and steady progress."

BIPARTISAN APPEAL

Bush, a Republican, and Bill Clinton, a Democrat, have set up a Web site, www.clintonbushhaitifund.org, to collect contributions from Americans and donors around the world.

Bush, who was widely criticized for his administration's response to Hurricane Katrina in 2005, urged Americans to give money, saying it is the most effective answer to the immediate crisis facing Haitians.

"I know a lot of people want to send blankets and water — just send your cash," Bush said. He promised to make sure "that your money is spent wisely."

Former President Clinton, who is also the U.N. special envoy to Haiti, said the earthquake would require expanding plans for long-term rehabilitation that were under way before the catastrophe.

On a hillside golf course, perhaps 50,000 people were sleeping in a makeshift tent city overlooking the stricken capital, the AP reported. Paratroopers of the U.S. 82nd Airborne Division flew there yesterday to set up a base for handing out water and food.

The U.N. has estimated that the quake damaged or flattened up to half of the buildings in hard-hit areas.

But the short-term challenge of moving people and huge aid shipments into the city through the damaged airport was proving daunting enough.

LOGISTIC PROBLEMS

Aid organizations looked for detours around the overwhelmed airport, with one runway, and quake-damaged seaport. Some were shuttling supplies overland from the neighboring Dominican Republic, but roads are poor and the going slow.

U.S. Air Force Capt. Dustin Doyle said the Air Force had taken charge of the airport to ensure that planes unloaded their cargo quickly, and then took off again to allow more planes in. France lodged a protest after two relief flights were turned away by U.S. air traffic controllers, the AP reported.

"The first few days some planes just couldn't land" because of the crowded tarmac and lack of control, Doyle said. From here, Doyle said, the U.S. Army will oversee moving the materials to a staging point either inside the airport premises or somewhere nearby. From that point, he said, aid agencies will pick them up for distribution.

"We're not going to just induce rioting by taking supplies and dropping them somewhere," Doyle said. "We want everything now, now, now too, but it's just that sometimes these things take time."

But that's exactly what people outside the airport wanted to happen.

Luciana Hasboun suggested that police and U.S. troops could deliver supplies directly to the population through local committees. Leaving it to aid agencies to set up distribution sites would be a problem for the elderly and injured, and lead to fighting among Haitians for the goods, Hasboun said.

Jean Maxime Paulroc agreed, saying: "The people are crooked. The (local aid) organizations are crooked.

"They always say if someone wants something to get done, they prefer the U.S. Marines to the U.N."