The United Nations and Red Cross increased their separate appeals for emergency funding over six months to more than half a billion dollars at a meeting here with some 60 donor nations.
UN Secretary General Kofi Annan told the meeting: "While no one today could have had the power to prevent the earthquake from happening, we do have the power to stop the next wave: the deaths and despair caused by freezing temperatures and disease, by lack of shelter, food and water."
Donors pledged an additional 580 million dollars in assistance for Pakistan in response to the pleas, the United Nations chief emergency relief co-ordinator Jan Egeland said. But it was unclear how much of the new pledges would go towards the world body's emergency appeal, which was increased from 312 million dollars to 550 million dollars before the meeting on Wednesday.
Some of the new pledges may be earmarked by governments for longer-term reconstruction, or other assistance, officials emphasised, hinting at disappointment.
"It's important to engage in reconstruction issues, but from our perspective the critical issue right now is emergency relief for the millions of people who are really in very desperate need," UN relief official Toby Lanzer said.
Egeland also called for the promises to be turned into "actionable contributions" to allow relief agencies to deliver shelter and medical care to some 3.3 million homeless or injured quake survivors.
So far the UN has collected just 111 million dollars in cash.
Nonetheless, he acknowledged that the race to deliver help before winter takes hold next month had been energised.
"It is a deadline. This is a line of life or death for tens of thousands if not hundreds of thousands of people in the Himalayas," he told reporters.
"With the resources made available today and the commitments that will come in the coming days, we will redouble our collective efforts."
UN Officials warned that many relief agencies were running out of funding, hampering the delivery of crucial shelter equipment or food to the area before snow threatens to ground the relief effort next month.
Annan urged governments and even individuals to overcome their weariness with a succession of disasters this year and to match the unprecedented outpouring of generosity that followed the Indian Ocean tsunami.
"We need the support of governments, private citizens, the private sector and anyone who can spare a euro, a pound or a dollar," he told journalists.
The International Federation of Red Cross and Red Crescent Societies, which also took part in the meeting, doubled its separate appeal for the quake victims to 152 million Swiss francs (117 million dollars).
The UN has been struggling to collect funding for emergency assistance in Pakistan. By contrast, the Red Cross appears to have generated a better response, receiving 42 million Swiss francs and pledges for a further 35 million, before it doubled its 73 million Swiss franc appeal on Wednesday.
In Geneva, Senate chairman, Mohammedmian Soomro, and PM's advisor Salman Shah outlined the extent of destruction of life and property caused by the 7.6 magnitude earthquake.
"This is the time when the world has to come to our support," Soomro said.