The UN has only received a fraction of its $312 million appeal launched three weeks ago. The UN tally so far includes $67.8 million in cash and another $33 million in pledges from donor governments for six months of emergency relief funding.
The world body warned this week that bad weather in coming days was likely to hamper helicopter flights in the region, while winter snowfall was expected to take hold in three weeks time.
"If we do not reach all the most seriously injured in isolated villages within two weeks, we will face a second wave of deaths", UN humanitarian affairs spokeswoman Elisabeth Byrs told AFP.
Kofi Annan is unusually due to take part in the meeting to press the case for a speedier response to the plight of the victims of the October 8 earthquake, alongside his emergency relief chief Jan Egeland, 65 countries, including Pakistan, have so far registered to take part, Byrs said.
Top level participants are expected to include French Foreign Minister Philippe Douste-Blazy, his Swiss counterpart Micheline Calmy-Rey, Britain's Overseas Development Minister and the head of the US government aid agency, USAID.
"We are very satisfied with the response. From the signs, we have its lining up very well," Byrs said.
"We'll take stock of the situation and the humanitarian response and look at the problems we need to confront as swiftly as possible. States will have a chance to announce their funding aims," she added.
EU humanitarian aid commissioner Louis Michel said on Monday that a "second humanitarian disaster" was looming for destitute survivors and more than 70,000 injured unless help arrives before winter.
The European Commission pledged an additional aid worth 13.6 million euros (16.4 million dollars) on top of the 66.4 million euros it has already released.
About 100 helicopters were ferrying aid around the Himalayan region and the top priority for donors now should be shelter equipment, including tents, said Byrs.
"We'll ask for a few more helicopters, but it's no longer the most essential thing. Now it's shelter, shelter, shelter," Byrs said.
There were signs that foreign relief deliveries to Pakistan were gaining pace.
The UN refugee agency said a chartered Boeing 747 cargo plane carrying 76 tonnes of supplies per flight was joining its Nato-run airlift of supplies into Pakistan, which was limited to 10 tonnes per flight.
"This will considerably shorten the amount of time that we need to get the remaining 600 tonnes of supplies from our warehouses in Turkey down to Pakistan," said Jennifer Pagonis, a spokeswoman for the UN High Commissioner for Refugees.
"Certainly, this is a race against time and the weather and we hope to get our material on the ground as soon as we possibly can," Pagonis added.