Unable to set an agenda for their first face-to-face encounter since Israel's withdrawal from the Gaza Strip, the leaders of Israel and the Palestinian territories decided Monday to postpone a tentatively scheduled summit for several weeks.

While both Israeli and Palestinian officials said that the meeting is likely to be in early November, the difficulty in agreeing on topics to be discussed underscored the challenge in turning the Israeli evacuation of Gaza into a sustained peace process.

The postponement also highlighted the domestic political pressures shaping Palestinian and Israeli peace overtures, complicating efforts to begin a U.S.-backed process toward a final resolution. In one sign of progress, Palestinian and Israeli officials announced Monday the formation of several committees to examine the status of Palestinian prisoners, fugitives and deportees and the transfer of additional West Bank cities to Palestinian control.

"We're engaged not in a single event, but in a complex and critical process," said Raanan Gissin, a spokesman for Israeli Prime Minister Ariel Sharon. "But we think there is enough common ground to reach an agreement on some of these issues."

Today's postponement marked the second time a meeting between Sharon and Palestinian leader Mahmoud Abbas has been delayed since the last Israeli troops left Gaza nearly a month ago. An Oct. 2 meeting was put off during an Israeli offensive in Gaza after radical Palestinian groups fired rockets into southern Israel.

Israeli and Palestinian officials have spent several days discussing the agenda for the summit that had been tentatively scheduled for Tuesday. The last meeting between the men was in June, but it was dominated by recriminations over violence running up to the Gaza withdrawal.

Palestinian officials now worry that Israel, enjoying a moment of international support for its unilateral exit from Gaza, does not want to negotiate over the future of the West Bank.

"This delay wasn't because of disputes or anger, but because we have to maximize our efforts to revive this peace process," said Saeb Erekat, the chief Palestinian negotiator. "We should begin a process of regaining the trust between us. That's what this is about."

Success is perhaps most pressing for Abbas, now facing a rising political opposition in the militant group Hamas and unrest among the younger generation within his own Fatah movement. But Sharon, facing a difficult party primary and general elections next year, must also take care not to be seen as giving up too much to the Palestinians without security pledges in return.

Abbas, elected in January to succeed the late Yasser Arafat, met here Monday with C. David Welch, the U.S. assistant secretary of state for Near Eastern affairs, to discuss the agenda for his planned Oct. 20 meeting with President Bush. Palestinian officials familiar with the talks said the Bush administration wanted to hear from Abbas about the security situation in the territories and the role that armed Palestinian groups, including Hamas, will play in upcoming national elections.

Hamas, formally known as the Islamic Resistance Movement, has asserted that its armed attacks were the reason Israel ended its 38-year presence in Gaza. The extent to which Palestinians believe those statements could determine Hamas's level of support when it fields its first candidates in parliamentary elections, now scheduled for January.

To show that negotiation is the more productive way of engaging Israel, Abbas is hoping to leave any summit with concessions on several issues, ranging from greater control of Gaza's borders, which are still monitored by Israel's military, to the release of some of the more than 7,000 Palestinians in Israeli prisons. Diana Buttu, an Abbas adviser, said the Palestinian leader wants Sharon to release at least 23 long-serving Palestinian prisoners who were scheduled to be let go under the 1993 Oslo accords.

Abbas also wants pledges that the Israeli military will leave five major West Bank cities as agreed to during a February summit in Sharm El-Sheikh, Egypt, something defense officials oppose. Sharon pulled back from two of those cities earlier this year. But the Israeli military reoccupied one of them, Tulkarm, after a July suicide attack inside Israel was staged from a nearby town.

"We didn't want to go into a meeting just for the sake of having a meeting," Buttu said. "The signal it would have sent to Washington was that there is no need for them to get involved, when they are indicating that they would like to."

Israeli officials contend the meeting should focus on the steps Abbas should take to consolidate Palestinian security forces, now a variety of often rival agencies, and rein in Hamas. The organization refuses to recognize Israel's right to exist.

Gissin, reiterating Sharon's position, said prohibiting Hamas from participating in the January elections unless it first disarms should be on the summit's agenda. The Bush administration, which designates Hamas as a terrorist organization, also contends it should be banned if it refuses to give up its guns. In recent weeks, the Israeli military has arrested more than 200 members of Hamas, including some likely candidates for parliament.