As U.S. Secretary of State Condoleezza Rice wrapped up her latest Middle East mission, Palestinian officials acknowledged Monday that a timetable to finish negotiations leading to establishment of a Palestinian state will not be finalized before an upcoming U.S.-sponsored peace conference.

But Palestinian Authority President Mahmoud Abbas, after meeting with Rice in the West Bank city of Ramallah, said negotiations carry their own nonnegotiable deadline: the end of President Bush's term in January 2009.

Rice's visit ended on an upbeat note, with Abbas saying there was "a real opportunity to achieve peace."

Palestinian and Israeli negotiating teams continue to work on a joint pre-conference declaration of mutual goals.

Abbas and other Palestinian officials have hinted they might skip the conference, which is scheduled for sometime in the next six weeks in Annapolis, Md., unless the joint statement includes specific proposals on core issues and a firm timeline for negotiations. Israeli officials, backed by Rice, prefer to leave the specifics to long-term negotiations after the conference.

On Monday, despite receiving almost none of what he demanded, Abbas indicated that he was committed to the process.

The generations-old Israeli-Palestinian conflict won't be solved "in days or weeks or even months, but we have hope," he said. "The negotiations are difficult and will continue to be difficult until the last moment."

Rice sounded a similarly optimistic tone.

"We appear to be on course to prepare seriously for continuous ongoing negotiations," she said. "The Palestinian people have waited a long time to achieve the dignity that comes from an independent state."

A final date for the Annapolis conference hasn't been set, and the U.S. has yet to issue formal invitations. America's Arab allies, including Saudi Arabia and Egypt, have yet to commit to high-level representation. Their support is considered to be crucial for a successful conference.

Israeli Prime Minister Ehud Olmert said Sunday that the Annapolis meeting would be "the jumping-off point for continued serious and in-depth negotiations which will not avoid any issue."

Speaking before a conference of the Brookings Institution's Saban Center for Middle East Policy, Olmert referred to the legacy of former Prime Minister Yitzhak Rabin, who was assassinated in 1995, shortly after signing the Oslo peace accords with the Palestinians.

"Rabin did not charge towards the peace process with excessive enthusiasm. More than anything, he exhibited doubt, hesitation, and was repeatedly tormented by the cost of peace and the risks it entailed," Olmert said. "However, when he saw a chance, he acted to realize it."

"This is Rabin's legacy. . . . This is a legacy to which I am obligated; this is a legacy according to which I intend to lead the state of Israel over the coming months."

Rabin's legacy remains a touchy subject in Israel. On Sunday night, fans of the Beitar Jerusalem soccer club booed throughout a moment of silence to mark the 12th anniversary of Rabin's death and chanted slogans praising his assassin.

Each side is calling for the other to fulfill its obligations under the U.S.-backed peace plan known as the "road map."

The plan calls for Palestinians to reform their security forces, round up unauthorized weapons and rein in militant groups. Israel's obligations include halting the construction of settlements, dismantling the dozens of settler outposts that have sprung up in the West Bank, lifting restrictions on Palestinian movement and reopening closed Palestinian offices in East Jerusalem.

Palestinians complain that Israel has fulfilled few of its commitments. They say they have fulfilled the majority of their own obligations, but the most important element from an Israeli perspective, reining in militant groups, has been a disaster.

The most prominent militant group, Hamas, now controls the Gaza Strip after routing Abbas' Fatah faction in June.

In the West Bank, which is still controlled by Fatah, Palestinian policemen traded gunfire with militants Monday in a refugee camp outside Nablus.