Secretary of State Condoleezza Rice opened an intense round of Mideast shuttle diplomacy Sunday, struggling to bring Israelis and Palestinians close enough to make a planned U.S.-hosted peace conference worthwhile.

The two sides are at bitter odds over an outline of a peace agreement that would be presented at next month's conference, and Rice sought to lower expectations her mission would finalize preparations for the gathering.

Underscoring her less-than-optimistic assessment, Israeli and Palestinians traded shots about the other's commitment to peace even as she arrived in the region. During her four-day visit, she will bounce between Israel and the West Bank, seeking a consensus.

Her hope is to close the gap as Israel and the Palestinian Authority try to forge an outline of an eventual peace deal and produce a joint statement for the conference. It is expected to held in Annapolis, Md., in late November.

But after Rice's first series of meetings, a senior State Department official hinted that the date could slide as the lead negotiators for the two sides will begin only this week to try to craft the document.

"This is going to take some time," the official told reporters on condition of anonymity in order to describe the private conversations. "This is going to require a lot of hands-on American diplomacy. These are really tough issues."

And on her flight from Moscow, where she held talks with Russian leaders, Rice said she did not believe her visit would clear the way for that statement or make enough progress so that conference invitations could go out.

"I don't expect out of these meetings that there will be any particular outcome in the sense of breakthroughs on the document," she told reporters on her plane. She said intends to return at least once to the Mideast before the conference.

Rice said she wanted to "help them narrow differences that they may have about what the nature of this document has to be."

"I do think it's important that they address the core issues in some fashion," she said. "I also think it's important that the document be substantive enough that it points that there is a way forward toward the establishment of a Palestinian state."

Israel is pressing for a vaguely worded document that would give it more room to maneuver. The Palestinians want a detailed preliminary agreement with a timetable for creating a Palestinian state as well was specifics on borders, sovereignty over disputed Jerusalem and a solution for Palestinian refugees — the "final status" issues.

Israel said Foreign Minister Tzipi Livni would lead negotiations with the Palestinian team led by Ahmed Qureia, a former prime minister.

Israeli Prime Minister Ehud Olmert told his Cabinet he did not believe the joint statement was a prerequisite for the conference. He repeated that in his two-hour plus meeting with Rice, according to his office.

The goal, Olmert said, "is to arrive at a joint statement during the international conference, even though the existence of such a statement was never a condition for holding this conference."

But the acting Palestinian foreign minister, Riad Malki, said his side would skip the conference without agreement on a statement.

"Without a document to resolve this conflict, we can't go to the conference next month," he said. "Olmert is looking for a public relations conference and one that will allow normalization with Arab countries. We will not help him in this."

Ahead of her meetings, Rice delivered a rare warning to Israel not to take any steps that might erode confidence in the peace process. "This is a very delicate time," she said. "It's just a time to be extremely careful."

Her comments referred to the renewal of a road project that Palestinians fear is intended to tighten Israeli control over strategic West Bank areas near Jerusalem. Israel says construction is not imminent and is meant to ease Palestinian movement.

But those assertions did little to ease concerns. Shortly after she landed, Israeli officials said they had decided to resume an archaeological dig near a hotly disputed Jerusalem holy site, drawing more Palestinian charges that Israel is trying to scuttle the conference.

Rice also met with Israeli Defense Minister Ehud Barak, who later issued a statement saying the military's freedom of movement in the West Bank was a "fundamental principle that must be demanded in the future as well."

The comments from Barak, who later headed to Washington for talks with the Bush administration, came despite long-standing Palestinian demands for a reduced Israeli presence in the West Bank.

Rice is on her third trip to the region since June, when the United States began to try to revive peace efforts after the Islamic militant group Hamas seized control of the Gaza Strip.

That takeover has left the moderate Palestinian president, Mahmoud Abbas, in control of just the West Bank. His expulsion of Hamas from the government has, in U.S. eyes, freed him to pursue a peace deal that would create a Palestinian state.

Also on Rice's schedule was dinner with the Palestinian prime minister Salam Fayyad, and talks Monday with Abbas in Ramallah. She will have second sessions with both sides on Wednesday.

To build Arab support for the conference, Rice plans stops in Egypt on Tuesday to see President Hosni Mubarak and in Britain on Thursday, where she will see King Abdullah of Jordan.

The participation of the those countries, the only major Arab nations to have signed peace deals with Israel, along with Saudi Arabia is considered key to the success of the conference. All three have expressed doubts about the effectiveness of the meeting.