Rice said the conference must be "substantive and advance the cause of a Palestinian state." Parties must not "simply meet for the sake of meeting," she said.
However, Rice did not detail the invitees or the objectives of the conference. Palestinians are pressing for a definitive peace deal, including a timetable for Palestinian statehood, while Israel is looking for a more limited declaration of intent to establish a Palestinian state.
But at a briefing en route to Andrew's Air-Force base Thursday, Rice deemed a timetable unlikely. "I think a timeline isn't wise at this point. We'll see if one is helpful later, but it isn't wise at this point. But I don't want to leave the impression that the roadmap has been pushed aside. I think ... it's still a reliable guide to a lot of the obligations that have to be met," she said, according to a State Department transcript.
Abbas and Olmert have held periodic talks over the past few months and have set up negotiating teams to try to work out an outline of a peace deal ahead of the conference, reported the Associated Press.
Abbas also said he would urge Rice to invite all relevant Arab states, including Syria and Lebanon, but said some Arab states are hesitant to commit to the conference before the objectives are made clear.
"I think many issues need to be clarified and I think it's the duty of the hosts of the conference," he said, according to the AP.
For its part, the Hamas-led government in the Gaza Strip contended that it wouldn't be bound by any agreements reached at the conference. Hamas took over the territory in June, and Abbas ejected the Islamic group from the government, creating a new Fatah-led government in the West Bank.
Rice's trip to the region was preceded by the Israeli government declaring the Gaza Strip a "hostile territory" and threatening to cut electricity and food supplies to the area to try to get Gaza militants from firing rockets at Israel.
Abbas called the decision "oppressive" and said it would increase the suffering of the people in Gaza, but he did not call off the peace process.