Negotiations between Abbas and Israeli Prime Minister Ehud Olmert have yielded little progress since Bush hosted a conference in Annapolis, Maryland, in November where the two leaders pledged to try to reach a peace deal by the end of 2008.
The U.S. administration now appears to be picking up the pace of Middle East diplomacy again after Bush failed to achieve a breakthrough on his last visit to the region in January.
Since Annapolis, the climate has been soured by the dispute over Israeli settlement expansion plans in the West Bank and by violence in and around Gaza, where Hamas cross-border rocket fire has drawn a tough Israeli military response.
Abbas wants Bush to press Israel to stop expanding its enclaves in the occupied West Bank but neither leader spoke publicly after meeting on Thursday about the Jewish settlements Palestinians see as a way of denying them contiguous territory.
Israel insists it has the right to build in major settlements it intends to keep under any future peace treaty.
Secretary of State Condoleezza Rice is going to the region next month before Bush, who is looking to shape a foreign policy legacy that encompasses more than the unpopular war in Iraq.
"The Palestinians and the Israelis have made halting progress," Perino acknowledged earlier, saying the administration was looking for ways to "reinvigorate their communication with one another".
But Bush will likely have a hard time squeezing serious concessions from either side as world leaders look increasingly to whomever will succeed him in January 2009.
TRUCE CONDITIONS
Speaking after meeting Egyptian intelligence chief Omar Suleiman in Cairo, Hamas' Zahar said the truce must include an end to the Israeli blockade of the coastal strip.
Suleiman, Egypt's main contact with Hamas and Israel, had agreed to call Palestinian factions to Egypt to discuss the offer and ensure Palestinian consensus, Zahar said.
"It was agreed with Minister Suleiman to invite the Palestinian factions next Tuesday and Wednesday to discuss the paper presented by our side," Zahar said.
Israel tightened a blockade on the Gaza Strip after Hamas seized control of the territory from Abbas' Fatah group last June.
A U.N. humanitarian agency on Thursday suspended its aid operations to hundreds of thousands of Palestinians in the Gaza Strip over lack of fuel supplies that had been restricted by Israel.
A shipment of fuel destined for the United Nations and Relief Agency was blocked by Palestinian farmers angry that they had been deprived of fuel.
