U.S. Secretary of State Condoleezza Rice was meeting with Palestinian President Mahmoud Abbas on Monday in hopes of finding common ground before a Mideast peace conference late next month.
After a first round of talks with Israeli leaders on Sunday, State Department officials indicated the conference, called by U.S. President George W. Bush, might have to be postponed.
The Israelis and Palestinians even differ on whether prior agreement is essential. After Israeli Prime Minister Ehud Olmert told Rice that a statement of principles would not be a condition, Palestinians were saying the opposite - that they would not attend the gathering without a meaningful document that covers all the main outstanding issues.
These are the same issues that have defied solution for decades - borders for a Palestinian state and the extent of Israel's withdrawal from the West Bank, sharing Jerusalem and the fate of Palestinian refugees.
While Israel has hinted at ceding Jerusalem's Arab neighborhoods, that has not satisfied the Palestinians. They, like the Israelis, claim sovereignty over the key holy site, where the Al Aqsa mosque compound sits atop the ruins of the biblical Jewish temples. Israel further angered the Palestinians on Sunday by approving resumption of an archaeological dig and renovation project just outside the holy site.
Palestinians have shown some interest in land exchanges that would give them the equivalent of all of the West Bank while allowing Israel to keep some of its settlements, but details and quantities are far from agreement.
No discussions over refugees have been reported. Palestinians traditionally have demanded the right of about 700,000 people who fled or were driven out during the war that followed creation of the state of Israel in 1948 to return to their original homes - along with millions of descendants. Israel rejects that as an attempt to destroy the Jewish state.
Palestinians also insist that the document include a solution for division of vital water resources. No talks have been reported on that issue.
Heads of negotiating teams have been appointed only in recent days - former Palestinian premier Ahmed Qureia last week and Israeli Foreign Minister Tzipi Livni on Sunday - and officials said they would meet for the first time later this week, just six weeks before the tentative date of the Mideast gathering.
After Rice's first series of meetings Sunday, a senior U.S. State Department official hinted that the date could slide.
"This is going to take some time," the official told reporters on condition of anonymity to describe the private conversations. "This is going to require a lot of hands-on American diplomacy. These are really tough issues."
Rice cautioned against expecting breakthroughs during her four days of talks, punctuated by a trip to Cairo and followed by talks in London with the king of Jordan.