nternational donors have pledged almost $4.5bn (£3.2bn) in aid to the Palestinians, chiefly to rebuild Gaza after Israel's recent offensive.
US Secretary of State Hillary Clinton said Washington would donate $900m, and vigorously seek to advance peace.
Palestinian leader Mahmoud Abbas told a summit in Egypt cash was "insufficient" without a political solution.
Israel, which has been fighting Gaza militants, refuses to allow building materials into Gaza for reconstruction.
Mrs Clinton told the conference in the Red Sea resort of Sharm el-Sheikh: "Our response to today's crisis in Gaza cannot be separated from our broader efforts to achieve a comprehensive peace."
During her first visit to the Middle East as top US diplomat, she said the aim of the aid was to "foster conditions in which a Palestinian state can be fully realised".
Some 1,300 Palestinians, of whom 412 were children, were killed and thousands of homes and businesses destroyed in December and January as Israel tried to bring an end to cross-border rocket attacks by Palestinian militants.
Hamas, which controls Gaza but is regarded by both the US and the EU as a terrorist organisation, was not invited to attend the one-day conference.
The movement welcomed efforts to rebuild Gaza but said it should have been asked to take part.
Hamas spokesman Fawzi Barhoum also told the BBC that donors had "politicised" aid by handing it to Mr Abbas's Palestinian Authority.
'One viable future'
Donations far exceeded the Palestinians' request for $2.8bn (£2bn). As well as Mrs Clinton's $900m, Saudi Arabia promised $1bn (£703m) for Gaza.
“ The situation at the border crossings is intolerable ”
Ban Ki-moon UN Secretary General
Mr Abbas said that while all the support was appreciated, "we insist on the pressing need to achieve substantial progress towards a just settlement [of the conflict with Israel]".
"We are all conscious that the reconstruction and development efforts will remain insufficient, powerless and threatened in the absence of a political settlement," he said at the conference.
UN Secretary General Ban Ki-moon said now was the "time to think freshly, to lead boldly".
"There is only one viable future: Palestinians and Israelis living side by side in peace and security," he told delegates.
British Foreign Secretary David Miliband said that "visible signs of progress" in the West Bank and Gaza were vital.
He added that Palestinians needed "a single government across the occupied territories" - a direct appeal for rival Palestinian factions to put aside their differences.
French President Nicolas Sarkozy, for his part, urged Hamas "to engage resolutely in searching for a political solution and engage in a dialogue with Israel".
Aid flows
Raising money for Gaza is the easy part, the BBC's Christian Fraser in Egypt says.
GAZA DESTRUCTION
# 14,000 homes
# 219 factories
# 240 schools UNDP estimates
The real business of the conference is the practicalities of how to get it to the people who need it most, he adds.
All but essential supplies are still subject to Israeli blockades at the crossing points into Gaza.
Building and raw materials deemed by Israel to be useful to militants as well as civilians have been banned.
Aid workers say items turned away at the border have included macaroni, lentils, paper and school books.
Mr Ban described the situation at the crossings as "intolerable".
"Aid workers do not have access. Essential commodities cannot get in. Our first and indispensable goal, therefore, is open crossings," he told delegates.
But he said it was also "essential" to ensure that illegal weapons were prevented from being allowed to enter Gaza.
Donor countries as well as Israel, which did not attend the conference, have stressed that they do not want aid to end up in the hands of Hamas.
"Like the international community, Israel does not want to see support to Hamas," Israeli government spokesman Mark Regev said. "We want to see support for the people of Gaza."
The Palestinian Authority has proposed that all aid to Gaza should be channelled through itself.
Although Israel and Western negotiators refuse to speak to Hamas, UN agencies working in Gaza do co-ordinate with the group.
UN relief agency Unrwa says it has contacts with Hamas "even at ministerial level", but strictly on technical issues related to the delivery of its humanitarian services in line with wider UN policy.
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