Israeli and Palestinian leaders are set formally to begin a new round of peace talks at the White House.
There has been scepticism over the drive in the region in question
US President George W Bush will meet with Ehud Olmert and Mahmoud Abbas alone before a rare three-way meeting.
It follows a conference on Tuesday when both sides agreed to engage in "vigorous" efforts to reach a peace deal by the end of 2008.
But the Palestinian group Hamas said the conference - from which it was excluded - had been a "failure".
Expectations had been low as representatives of more than 40 countries and international agencies gathered in Annapolis, Maryland, ahead of Tuesday's conference.
But in a joint statement concluded with only minutes to spare before the conference formally opened, the two sides agreed to launch negotiations for a treaty "resolving all outstanding issues, including all core issues without exception".
Both sides have said those "core issues" will include the thorny so-called "final-status issues" - the future of Jerusalem, borders, water, refugees and settlements - which have scuppered previous attempts at a peace deal.
Israeli Prime Minister Olmert and Palestinian Authority President Abbas will formally inaugurate the new peace drive in meetings in the White House on Wednesday, said US Secretary of State Condoleezza Rice, in a closing news conference on Tuesday.
According to the agreement, they will go on to meet every other week.
In addition, teams of negotiators will be led by a joint steering committee which will meet for the first time on 12 December.
In Tuesday's conference, Mr Bush committed himself to spending the rest of his presidency - until January 2009 - working towards "an independent democratic viable Palestinian state".
"Such a state will provide Palestinians with the chance to lead lives of freedom, purpose and dignity," Mr Bush said.
"And such a state will help provide Israelis with something they have been seeking for generations: to live in peace with their neighbours.
"This is the beginning of the process, not the end of it," he said.
Mr Abbas repeated demands including that Israel stop building settlements, and release some of the thousands of Palestinian prisoners in Israeli jails.
"Neither we nor you must beg for peace from the other," he said.
"It is a joint interest for you and us."
Mr Olmert said he had come to Annapolis despite the obstacles posed by continuing violence against the people of Israel.
"We want peace. We demand an end to terror, an end to hatred. We are prepared to make a painful compromise rife with risks, in order to realise these aspirations," he said.
In a closing news conference, Ms Rice said the event had demonstrated "unambiguously" that the new initiative had international support.
Nations will be asked to provide financial support for Palestinian aid programmes at a donors' conference in Paris in mid-December.
Observers say the fact that the summit is being hosted by the US and has attracted the participation of Saudi Arabia and Syria, two Arab states that do not recognise Israel, is critical to its chances for success.
But following the main speeches, both countries cautioned that a "comprehensive peace" which saw relations normalised between Israel and Arab countries was dependent on Israel first meeting demands to withdraw from occupied land.
Expectations going into Annapolis have been low because every other attempt at negotiation between the Israelis and the Palestinians has failed, says the BBC's Jeremy Bowen at the conference.
However, there are grounds for optimism, says our correspondent: the Americans are behind the talks, there is no plan B and the consequences of failure could be bloody.
The absence of the Palestinian faction Hamas, which is designated a terrorist organisation by the US, the EU and Israel, could also make negotiating a deal problematic.
Hamas controls the internal affairs of the Gaza Strip and says it will not be bound by anything decided in Annapolis.
Following the conference, Hamas spokesman Sami Abu-Zuhri said it had only achieved "a declaration of the beginning of negotiations between the Palestinians and Israelis and not a declaration of an agreement between them.
"This by itself is a sharp proof of the failure of the Annapolis meeting," he said.
In Gaza on Tuesday, tens of thousands of Hamas supporters demonstrated against the talks.
In the West Bank - a Fatah stronghold - police violently broke up some demonstrations, with one person killed in clashes in Hebron.