The Palestinian and Israeli prime ministers are due to meet on Saturday evening for the highest-level talks between the two sides for more than two years.
Abu Mazen wants an Israeli commitment to the peace plan
It will be the first meeting between Ariel Sharon and Mahmoud Abbas, also known as Abu Mazen, since the new reformist Palestinian prime minister took office last month.
The two men are expected to discuss the latest Middle East peace plan, known as the roadmap, which proposes a series of steps leading to the creation of a Palestinian state in 2005.
Importantly, this is the first high-level meeting between Israelis and Palestinians since the end of the war in Iraq.
Since bringing about "regime change" in Baghdad, the Bush administration has pledged to make the revival of the Middle East peace process an urgent priority.
ROADMAP MAIN POINTS
Phase 1 (to May 2003): End of terrorism, normalisation of Palestinian life and Palestinian political reform; Israeli withdrawal and end of settlement activity; Palestinian elections
Phase 2: (June-Dec 2003) Creation of an independent Palestinian state; international conference and international monitoring of compliance with roadmap
Phase 3 (2004-2005): Second international conference; permanent status agreement and end of conflict; agreement on final borders, Jerusalem, refugees and settlements; Arab states to agree to peace deals with Israel
It agreed to the long-delayed publication of the roadmap - and Colin Powell, the US Secretary of State, visited the region a week ago to launch it.
Abu Mazen wants to hear from Mr Sharon that Israel unequivocally accepts the plan.
But Israeli officials have come up with 14 reservations - and Mr Sharon intends to discuss these, not with Abu Mazen, but with President Bush, whom he is due to see in Washington on Tuesday.
For the Palestinians, one of the main requirements of the roadmap is a complete Israeli settlement freeze.
But Mr Sharon said in an interview a few days ago that the issue was not on the horizon. In his eyes the crucial issue is security.
If the violence goes on, as it has for more than two-and-a-half years, then, he argues, Israel cannot be expected to carry out its side of the bargain.
The Israeli prime minister's calculation is that President Bush is pre-occupied with getting re-elected next year, and will not want a bruising confrontation with the pro-Israel lobby in the US.
So, although a new phase of Middle East peacemaking is unfolding, it is doing so amid a distinct absence of optimism.