Among those stranded in Thailand were 10 members of the USAID Disaster Assistance Response Team. Air Force transport planes and helicopters packed with supplies also sat waiting for a greenlight.
"We are in a long line of nations who are ready, willing and able to help, but also, of course, in a long line of nations the Burmese don't trust," U.S. Ambassador Eric John told reporters in Thailand's capital, Bangkok.
"It's more than frustrating. It's a tragedy," he said. Each day of delay means "a lot more people suffering," he said.
Myanmar's isolationist regime issued an appeal for international assistance after winds of 120 mph and a storm surge up to 15 feet high pounded the Irrawaddy delta Saturday.
But the junta has been accused of dragging its feet despite emerging reports on entire villages submerged, bodies floating in salty water and children ripped from their parents arms.
"My children were crying all night. There is not enough food. There will be no food this evening," said Daw Thay, who took refuge in a monastery with her three children and her 99-year-old mother in a town 60 miles south of Yangon, the country's biggest city.
Daw Thay, 42, said monks were going without food so others could eat.
"We share what we have but there isn't enough. So they (the monks) give the food to the children and the old people first," she said.
Juanita Vasquez, a UNICEF worker in Myanmar, said Thursday that the most dramatic scene she's witnessed were children who have lost or become separated from parents.
There are "more children roaming around this area looking for their families," she said in a telephone interview from Yangon. "We don't know at the moment how many have lost their parents and relatives."
In the swampy delta, a horrible stench rose from corpses and dead animals, bloated and floating in the water. Someone had written on a black asphalt road in Kongyangon village: "We are all in trouble. Please come help us." A few feet away, the desperate plea, "We're hungry."
Tired of waiting for help in Yangon, red-robed monks, other civilians and dozens of soldiers cleared piles of debris and toppled billboards from streets and cutting branches off uprooted trees.
"They've started doing the clean up themselves," Aye Chan Naing, chief editor of Democratic Voice of Burma, said as a light rain showered down. "They are volunteers."
Public transportation was slowly coming back to life in the city, with some trains operating, and cars formed lines three miles long to get rations of two gallons of gasoline.
The cyclone blew off the roof of opposition leader Aung San Suu Kyi's dilapidated bungalow in Yangon and cut off its electricity, a neighbor said, speaking on condition of anonymity because of the sensitivity of the subject. Suu Kyi, who received a Nobel Peace Prize for her pro-democracy activism, has been under house arrest for years.
More than 20,000 are known dead and tens of thousands more are listed as missing, and the U.N. estimates more than 1 million people are homeless in Myanmar, which also is known as Burma.
Four airplanes carrying high-energy biscuits, medicine and other supplies reached Yangon on Thursday, U.N. officials said. Two of four U.N. experts who flew in to assess the damage were turned back at the airport for unknown reasons, but the other two were allowed to enter, said John Holmes, the U.N. relief coordinator.
By rejecting the U.S. aid offer, the junta is refusing to take advantage of Washington's enormous ability to deliver aid quickly, which was evident during the 2004 Indian Ocean tsunami that killed 230,000 people in a dozen nations.
The first foreign military aid following that disaster reached the hardest-hit nation, Indonesia, two days later. The most significant help came when U.S. helicopters from the USS Abraham Lincoln began flying relief missions to isolated communities along the Indonesian coast.
It was the biggest U.S. military operation in Southeast Asia since the Vietnam War.
With the Irrawaddy delta's roads washed out and the infrastructure in shambles, large swaths of the region are accessible only by air, something few other countries are equipped to handle as well as the United States.
Tim Costello, chief executive of World Vision Australia, said that "it's certainly the case that the Americans, as they showed in the tsunami, have extraordinary capacity."
The U.S. government, which has strongly criticized the junta's suppression of pro-democracy activists, will have to convince the generals that Washington has no political agenda, Costello said.
"Clearly we all know the political context there, and I think it's going to take a little bit more time for a breakthrough," he said.
Gordon Johndroe, President Bush's national security spokesman, said the U.S. was working to gain permission to enter Myanmar.
One American official, Ky Luu, director of the U.S. office of foreign disaster assistance, created a stir by saying one option being considered was air-dropping aid without permission. But Defense Secretary Robert Gates quickly said he couldn't imagine that happening.
Prime Minister Samak Sundaravej of Thailand offered to negotiate on Washington's behalf to persuade Myanmar's government to accept U.S. aid.
France is arguing that the U.N. has the power to intervene without the junta's approval to help civilians under a 2005 agreement that the world body has a "responsibility to protect" people when governments fail to do it. That agreement did not mention natural disasters.
French Foreign Minister Bernard Kouchner and British Foreign Secretary David Miliband asked Myanmar's junta to "lift all restrictions on the distribution of aid." Separately, Kouchner said France would make $3 million available to French aid groups operating in Myanmar.
The Association of Southeast Nations appealed to the international community to send relief supplies through Thailand.
"Please keep the help coming, keep the contributions coming, and if you have to, go to Thailand, park there and wait for redistribution from there," said ASEAN secretary-general Surin Pitsuwan.
The U.S. military sent more humanitarian supplies and equipment to a staging area in Thailand on Thursday. A C-17 transport plane brought in water and food, joining the two C-130s already in place, Air Force spokeswoman Megan Orton said at the Pentagon. Another C-130 loaded with supplies was on its way, she said.
The U.S. Navy also has three ships participating in an exercise in the Gulf of Thailand that could help in a relief effort, including an amphibious assault ship with 23 helicopters.
China, Myanmar's closest ally, urged the junta to work with the international community.
The London-based human rights group Amnesty International said some donors were delaying aid for fear it would be siphoned off to the army. The World Food Program's regional director, Anthony Banbury, indicated the U.N. had similar concerns.
"We will not just bring our supplies to an airport, dump it and take off," he said.
The U.N. refugee agency said it was assembling a truck convoy to take supplies from Thailand to Yangon, but it would take days to put the shipment together and up to two weeks to reach victims.
Myanmar's state media said Cyclone Nargis killed at least 22,997 people and left 42,019 missing, mostly in the Irrawaddy delta. Shari Villarosa, who heads the U.S. Embassy in Yangon, said the number of dead could eventually exceed 100,000 because of illnesses.
Asked about the death estimate, Costello of World Vision said hours after arriving in Yangon, "That extraordinary volume of rain, of wave, of wind just crushing everything, snapping everything in its wake, that death toll I think could be conceivable." He said some 60,000 people were unaccounted for.
The World Health Organization received reports of malaria outbreaks in the worst-affected area, and said fears of waterborne illnesses from dirty water and poor sanitation was a concern.
Myanmar's state television Thursday showed the prime minister, Lt. Gen. Thein Sein, distributing food packages to the sick and injured in the delta and soldiers dropping food over villages. The date of the distribution was not given.
Although most Yangon residents were preoccupied with trying to restore their lives, activists wrote fresh graffiti on overpasses, including "X" marks - a symbol for voting "no" in a referendum Saturday on a new constitution. Voting has been postponed until May 24 in Yangon, some outlying areas and parts of the delta.
U.N. Secretary-General Ban Ki-moon called on the junta to postpone the referendum entirely and "focus instead on mobilizing all available resources and capacity for the emergency response efforts."
