"At the moment, the emphasis is on the need for road engineers. If we can open the roads, that would solve everything," World Food Programme spokeswoman Mia Turner said.
"We're thinking more than 2,000 villages have to be reached and they have to be reached by roads," she said two weeks after the shattering earthquake killed more than 50,000 people and wrecked the few roads which wound high into the hills.
"If these people were connected, we wouldn't be carrying stuff up and down mountains on mules," she said as another train of the rented animals set off up into the hills from a village above the destroyed Pakistani Kashmir capital of Muzaffarabad.
Each mule can carry 100 kg (220 pounds), but like everything else in the disaster zone, they are in short supply.
U.N. officials said more helicopters were needed to get tents out before the harsh Himalayan winter descends in a few weeks.
"The top priority overall is tents and emergency shelter," U.N. coordinator Jan Vandermoortele said. "We need helicopters, a lot of helicopters and all types of helicopters."
The death toll is expected to rise substantially, with unknown numbers of people laying buried in the rubble of cut off villages.
More than 74,000 people are known to have been injured and opening the roads would also allow the many, many more in cut-off villages to get medical treatment without which they face death.
The helicopter aid fleet, which Vandermoortele said had only 50 operational at any one time, cannot deliver enough or reach everywhere and pilots report villagers waving red or orange flags to signal they needed help, Turner said.
Some were even trying to clear areas for helipads and marking them with an H, the international symbol for such landing spots.
ROUND THE CLOCK
The Pakistani army is working around the clock to open roads broken, covered by landslides or swept away by the October 8 quake in Pakistani Kashmir and adjoining North West Frontier Province.
Lieutenant-General Salahuddin Satti said he hoped the road up Pakistani Kashmir's Jhelum valley would be re-opened in a week, but it would take six weeks for the nearby Neelum valley.
In some parts of Pakistani Kashmir, people are desperate enough to fight each other for food aid or loot supply trucks.
"They are worse than vultures," said Mohammad Ishaq Khan after two truckloads of food and tents he sent to his native Kashmir village from Lahore were looted before they got there.
Hopes of a massive airlift to bring survivors to safety were dashed on Friday when NATO turned down a United Nations appeal.
The U.S.-dominated military alliance said it would send up to 1,000 troops to help, but would not stage an airlift.
"It will help a lot," Vandermoortele said, who, like other aid officials complained the world was not doing enough. "But we need more, we need much more, and we need it much faster."
But NATO will send only a few more helicopters to join the 40 that members of the alliance have sent.
Helicopters are the only means of getting quickly deep into the hills. The nearest are in India, where the quake killed 1,300 people on its side of Kashmir, but it has fought two of its three wars with Pakistan over the region, which both claim.
Pakistani President Pervez Musharraf told India he would accept helicopters, but only if they came without crews given the enormous political sensitivity. India said no.
Musharraf told the BBC he was ready to accept all other help, and talks had to be held with India on how the de facto border dividing Kashmir could be opened for the benefit of survivors.
But he also expressed disappointment that the world had not come forward with pledges of money to rebuild the shattered region, where the quake wiped out entire towns and villages.
"I know we have been donated about $620 million or something, which is totally inadequate," he said. The cost would be more than $5 billion, he added.
The United Nations has received just $57 million in firm commitments and $33 million in promises toward its $312 million appeal for Pakistan, a spokeswoman said in Geneva.
An estimated two million or more people are homeless but tents able to withstand the bitter Himalayan winter are scarce and Pakistan pleads daily for the world to send more.
U.N. coordinator Jesper Lund said international aid agencies planned to send 83,000 tents -- "all they have in the world." "But it's still a drop in the ocean," he said.
Another aid official said up to 541,000 tents were needed but with global supplies limited, the relief operation could come up 200,000 short.