Nations have been called upon to boost funds to prevent the collapse of a UN agency working with an estimated four million Palestinian refugees.
Decades of conflict have impoverished Palestinians
The UN Relief and Works Agency (Unrwa) has seen a drop in funding from $200 a year for each refugee to $70.
The largest conference yet on the issue opened in Geneva on Monday, attended by 70 countries and 30 organisations.
Some delegates told of "donor fatigue" amid repeatedly failed attempts to find a peaceful solution to the conflict.
UN Secretary-General Kofi Annan said it would be "tragic and worrying" if Unrwa's work could not continue.
"We are already seeing the consequences of under-funding ... in over-crowded classrooms and clinics, and in decaying Unrwa infrastructure," he said in a message to the conference.
"There is real concern that if these trends continue, the key human development strengths of the Palestine refugee population will begin to unravel."
He pointed out that the number of Palestinians in Gaza and the West Bank relying on Unrwa for food aid had risen from 130,000 to 1.1 million since September 2000.
In the same period, the number of Palestinians living below the poverty line had tripled from 20% to 60%, with an increasing reliance on Unrwa's health services.
Although most agree that a political solution is the only answer in the long-term, Unrwa stresses that politics are not on the agenda at Geneva, says the BBC's Imogen Foulkes.
Unrwa chief, Peter Hansen, told the conference that investing in young people's education could bring peace.
"Will their role model be the suicide bomber or will it be a graduate of a teacher's college who has a future as a productive member of society? And that is really a very major choice we are facing now."
The US is the largest contributor to the agency, and its donations have kept pace.
But those of European countries and other donors have been declining in recent years.
US Assistant Secretary of State Arthur Dewey urged donors to "do their share".
"This cannot continue, donors must restore previous levels of assistance so that the appeals are fully funded as they were initially," he said.
Some donor countries have been frustrated to see their aid projects being destroyed by the conflict, says our correspondent.
2003 CASH SHORTFALL
Planned budget - $321.1
Actual budget - $310
Planned Emergency Fund - $196
Actual Emergency Fund - $93
Sweden's representative at the conference, Thomas Hammarberg, said they did not want to throw good money after bad.
"There is a donor fatigue when it comes to the Palestinian refugees on all sides, frankly," he said.
"I mean the real reason, of course, is that there is no solution to the conflict and those who suffer from that are the refugees."
On the eve of the conference, a senior World Bank official warned that poverty was undermining the standing of the Palestinian Authority and threatening Israeli security.
Nigel Roberts, World Bank representative in the West Bank and Gaza Strip, said per capita GDP had fallen by 40%.
"The security measures that Israel has implemented over the past four years have essentially shredded the web of transactions that the Palestinian economy depends on," he said.
The decline, he added, played into the hands of Palestinian militant groups like Hamas competing with the Palestinian Authority.