JERUSALEM — At the outset of Secretary of State Rice’s latest diplomatic mission to the Mideast, Israel’s top negotiator today acknowledged problems trying to frame a blueprint for a peace deal with the Palestinian Arabs.

The two sides are at odds over whether a plan should spell out ways to resolve issues that have derailed peace talks in the past. Those mainly are final borders between Israel and a future Palestinian Arab state, sovereignty over disputed Jerusalem and a solution for Palestinian Arabs who became refugees after Israel’s creation in 1948.

Israeli and Palestinian Arab teams have been meeting in hopes of reaching the outlines of an agreement, which they hope to present at an American-hosted Mideast conference expected this year.

The Palestinian Arabs are pushing for a detailed agreement. Israel wants a more vague document that would give it flexibility. The Palestinian Arabs also want a deadline for establishing a state, even though earlier deadlines have been set and ignored.

“There is no tension in the meetings, there is a good atmosphere, in fact, but yes, there are problems,” Foreign Minister Tzipi Livni said before meeting with Ms. Rice. The chief American diplomat is trying to narrow gaps ahead of the peace conference.

Mr. Livni, Israel’s lead negotiator, did not elaborate. But her acknowledgment of problems was a departure from Israel’s past refusals to publicly discuss disputes with the Palestinian Arabs as they try to cobble together the joint platform.

The Palestinian Arabs, by contrast, openly have discussed their dissatisfaction with Israel’s desire for vagueness and its objection to drafting a timeline for an accord.

The Palestinian Arabs’ chief negotiator, Ahmed Qureia, said the two sides have yet to begin discussing the main issues. “We are still in the beginning and time is short,” he said.

The Palestinian Authority president, Mahmoud Abbas said “we are in a race with time” to produce a document that can be the basis for negotiations.

An outline for a peace deal is supposed to be the centerpiece of the international conference that President Bush hopes will include major Arab states, including some that do not recognize Israel. The initial, outline agreement would provide a springboard for full-fledged negotiations on producing a Palestinian Arab state.