WASHINGTON — The Bush administration was able to declare a clean sweep when Syria, the last Arab world holdout, said Sunday it would attend this week's high-stakes Mideast peace conference.

But as 16 Arab nations and the Arab League prepared to sit down with Israel for the first time in more than a decade, Israeli Foreign Minister Tzipi Livni made it clear they should not expect to dictate the contours of Israeli-Palestinian negotiations.

League members grudgingly agreed a few days ago to send their foreign ministers to the conference, meant to renew Israeli-Palestinian peace talks after a violent, seven-year lull in negotiations. Most members do not have ties with the Jewish state.

Syria had threatened to skip the three-day meetings in Annapolis, Md., and Washington, if they did not address the Golan Heights, a strategic plateau Israel captured from Syria in the 1967 Mideast war and later annexed. But with that issue added to the agenda, the deputy foreign minister, Faysal Mekdad, will participate, according to Syria's state-run news agency.

Nonetheless, the absence of Foreign Minister Walid al-Moallem appeared to indicate that Syria was not entirely confident the conference would address its concerns over the territory.

Israeli Prime Minister Ehud Olmert saw the appearance of a high-ranking Syrian official as a positive development.

"The meetings are clearly about the Israeli-Palestinian process, but could be the beginning of new avenues to peace in the Middle East," said the prime minister's spokeswoman, Miri Eisin.

But she and Livni disputed Syria's account of the conference agenda and insisted that the Golan was never explicitly mentioned.

Secretary of State Condoleezza Rice has said the United States would give room for other regional conflicts to be aired at the conference, including the Golan Heights. "If Syria chooses to come and wants to speak to its issues ... certainly nobody is going to rule it out of order," she said last week.

Even before Syria's announcement, Livni expressed confidence that Syria would attend. She reasoned that a session on the search for a comprehensive Mideast peace would give the Syrians a forum to press their position.

On the flight to Washington with Livni, Olmert said Israel would "favorably" consider negotiations with Syria if conditions ripened. Israel first wants Syria to break out of Iran's orbit and stop harboring Palestinian and Lebanese militants opposed to Israel's existence.

Surveying past peace efforts, Livni suggested that a lack of Arab backing contributed to the failure of the last round of Israeli-Palestinian talks, which collapsed amid bloodshed in early 2001. The Arab world, she said, "should stop sitting on the fence."

"There isn't a single Palestinian who can reach an agreement without Arab support," she said. "That's one of the lessons we learned seven years ago." But, Livni added, "it is not the role of the Arab world to define the terms of the negotiations or take part in them."

Arab states had been reluctant to attend the gathering, which starts Monday in Washington. They feared it would give Israel a public-relations boost while yielding little political benefit for the Palestinians.

But they decided to come to the first large-scale Arab-Israeli gathering since a 1996 meeting in Egypt. That is largely because they wanted to bolster moderate Palestinian President Mahmoud Abbas and keep him from making damaging concessions to Israel in talks that are to follow the conference. Abbas has been badly weakened by the Islamic Hamas group's violent takeover of the Gaza Strip in June, which left him in control of just the West Bank.

The Arab League has proposed offering normalized ties with Israel if the Jewish state cedes all land captured in the 1967 Mideast war and agrees to a solution for Palestinian refugees who lost their homes in Israel following the country's founding in 1948.

Israel opposes a complete territorial pullback and the repatriation of Palestinian refugees to Israel. It initially rejected the Arab proposal, first presented in 2002. But over the past year Olmert has said it could be useful in new talks.

Ahead of the conference, Israeli and Palestinian delegations were making a last-ditch effort to nail down agreement on where the talks would head after this week.

The Palestinians want the joint statement to address, at least in general terms, the central issues of final borders, claims to Jerusalem and the fate of Palestinian refugees.

Israel wants a broader and vaguer statement that would allow more room for maneuvering. It says the haggling on those issues should take place in the private talks that are to begin after the conference concludes on Wednesday.

"I hope Annapolis will allow the launching of serious negotiations on all the core issues that will lead to a solution of two states for two peoples," Olmert told reporters on the plane.

Abbas acknowledged that negotiations on the joint statement were in trouble.

"The positions with the Israelis before Annapolis are still far apart, and the negotiations are still ongoing," Abbas said in comments published Sunday in the Palestinian newspaper al-Ayyam.

Despite the differences, Abbas said he was committed to doing everything possible to hammer out an agreement in the coming year. Both Israel and the U.S. have said they hope to clinch a deal before Bush leaves office in January 2009.