Israel and the Palestinians are due to announce a formal ceasefire to halt four years of bloodshed when their leaders meet for a landmark summit in Egypt tomorrow.
Israel's Prime Minister Ariel Sharon and Palestinian President Mahmoud Abbas are to meet in the Red Sea resort of Sharm el-Sheikh for the highest-level meeting between the sides since a Palestinian uprising broke out in 2000.
As well as stopping the violence, the summit hosted by Egyptian President Hosni Mubarak and attended by Jordan's King Abdullah is billed as a step towards reviving the internationally-backed "road map" for a Palestinian state alongside a secure Israel.
Palestinian and Israeli officials said the deal on a truce had been reached in pre-summit talks. "We have agreed to declare a mutual ceasefire," said Mr Mohammad Dahlan, a close Abbas aide.
An Israeli official said: "The Palestinians are expected to announce an end to terrorism and violence. We will announce a halt to military operations on condition there is an end to terrorism and violence."
But it was unclear whether the ceasefire would be respected by Palestinian militants, who have followed a de facto truce for more than two weeks at the behest of Mr Abbas.
In Gaza, Hamas leader Mr Mahmoud al-Zahar said the Islamic militant group hoped Mr Abbas would not make any declaration without getting approval from the various militant factions.
The factions have said Israel's promise to free 900 out of 8,000 Palestinian prisoners, to pull back troops from some West Bank cities and to stop targeting top militants are not enough.
US President George W Bush said it was clear the two sides were gaining each other's trust and has invited both Mr Abbas and Mr Sharon to Washington for separate meetings in March or April.
He said he was impressed by Mr Abbas' commitment to "fighting off terror" and appreciated Israel's help in letting the Palestinians' election go forward in December.
"What you're watching is a process unfolding where people are becoming more trustworthy," he said.
Ending a visit to the Middle East , Ms Rice said: "There should be no doubt about the commitment of the United States to this process at this time - no doubt about the commitment of the president, no doubt about my personal commitment."
She also announced that Lt Gen William Ward would act a security co-ordinator to protect the peace moves.
"This is the most promising moment for progress between Palestinians and Israelis in recent years," Rice said. "I depart the region confident of the success of the meeting tomorrow between President Abbas and Prime Minister Sharon."