A huge US aircraft carrier arrived off the coast of the typhoon-hit Philippines Thursday, offering hope of a dramatic uptick in aid to destitute survivors as officials buried scores of rotting corpses.

The USS George Washington, with 5,000 sailors aboard, headed an eight-strong flotilla of US vessels bearing badly needed equipment, supplies and expertise for the thousands left homeless and hungry by one of the strongest storms in history.

But almost a week after Super Typhoon Haiyan swept through the country's central islands, killing thousands and leaving a security vacuum in its wake, desperation was still apparent and many of the dead remained unburied.

"I do feel that we have let people down," conceded United Nations humanitarian aid chief Valerie Amos, who had visited the shattered city of Tacloban on Wednesday.

"Those who have been able to leave have done so. Many more are trying. People are extremely desperate for help," she told reporters in Manila.

"We need to get assistance to them now. They are already saying it has taken too long to arrive. Ensuring a faster delivery is our... immediate priority."

The world body's leader Ban Ki-moon, currently in Latvia, later added UN agencies and teams "are on the ground to provide the necessary humanitarian assistance".

"Especially in the southern part there are tens of thousands of people exposed to the elements. We are doing everything possible to rush assistance to those who need it."

Around 110 corpses were interred in a mass grave Thursday before heavy-digging machinery broke down, Tacloban mayor Alfred Romualdez said.

They were placed at the bottom of a huge pit that is expected to be several layers deep by the time it is covered over with earth.

"There are still so many cadavers in so many areas. It's scary," Romualdez told AFP, adding that retrieval teams were struggling to cope.

"There would be a request from one community to collect five or 10 bodies and when we get there, there are 40," he said, describing aid agencies' response to the crisis as too slow.

US President Barack Obama urged Americans to donate generously to their former Asian colony.

US officials said relief channels were slowly opening up with the reopening of a main road.

Ships and planes from Asia-Pacific nations and Europe are also converging on the Philippines, bearing food, water, medical supplies, tents and other essentials to a population in dire need of the basics of life.

Prime Minister David Cameron dispatched the biggest vessel in Britain's own fleet, a helicopter carrier, while heavy transport planes carrying equipment such as forklift trucks have already arrived.

The Disasters Emergency Committee (DEC), a coordinating body for British aid charities, said it had raised 23 million pounds ($37 million) in the first 48 hours of launching an appeal for the Philippines.

"The public's reaction to the sheer devastation that has been left by Typhoon Haiyan is quite simply remarkable. We are so grateful for the huge amount of donations which are vital to fund the work done by our emergency teams," DEC chief executive Saleh Saeed said.

'An atmosphere of fear and depression'

But on the ground, the meagre aid that was getting through was still inadequate, with distribution hampered by fears of armed looters and by broken infrastructure.

Sick or injured people lie helplessly among the ruins of buildings, while those with the energy try to leave a place that resembles hell.

Efren Nagrama, area manager at the civil aviation authority, said conditions were "very dire now" as he surveyed the filthy stream of humanity at Tacloban's battered airport clamouring to get a flight out.

"You see hundreds coming to the compound every day. People who have walked for days without eating, only to arrive here and be made to wait for hours or days under the elements," he said.

"People are pushed to the tipping point -- they see relief planes but cannot get to the food nor get a ride out. There is chaos."

Mayor Romualdez said the people of Tacloban needed an "overwhelming response" from aid organisations and the government.

"We need more manpower and more equipment," Romualdez pleaded. "A six-day-old body is quite heavy. You would need three or four people to carry it.

"I cannot use a truck to collect cadavers in the morning and then use it to distribute relief goods in the afternoon," he added.

"Let's get the bodies out of the streets. They are creating an atmosphere of fear and depression."

City officials estimate that they have collected 2,000 bodies but insist many more need to be retrieved. The UN fears that 10,000 people may have died in Tacloban city alone, but President Benigno Aquino has described that figure as "too much".

The Philippine coastguard on Thursday confirmed the death of a 69-year-old Dutch tourist, whose body was found on Monday near the western Philippine island of Palawan.

While the retrieval of the dead gets going, there are growing fears for the health of those who survived.

The World Health Organisation says there are significant injuries that need to be dealt with -- open wounds that can easily become infected in the sweltering tropical heat.

Experts warn that a reliable supply of clean drinking water is vital if survivors are not to fall victim to diarrhoea, which can lead to dehydration and death, especially in small children.

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