The Bush administration was able to declare a clean sweep on Sunday when Syria, the last Arab world holdout, announced it would attend a high-stakes Mideast peace conference in the U.S. this week.

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 that they should not expect to dictate the contours of Israeli-Palestinian negotiations.

Livni spoke days after Arab League members grudgingly agreed to send their foreign ministers to the much-anticipated U.S.-hosted conference, meant to renew Israeli-Palestinian peace talks after a violent, seven-year lull in negotiations. Most do not have ties with Israel.

Damascus had threatened to sit out the gathering in Annapolis, Maryland, if it did not address the Golan Heights, a strategic plateau Israel captured from Syria in the 1967 Mideast war and later annexed. And after the Arab League meeting on Friday, Syria said it would study the agenda before deciding whether to attend.

On Sunday, Syria's state-run news agency announced that Damascus would send its deputy foreign minister, Faysal Mekdad, to the gathering because the Golan was added to the conference agenda. But Syria's decision not to send Foreign Minister Walid al-Moallem appeared to indicate that Damascus was not entirely confident the conference would address its concerns over the territory.

A spokeswoman for Israeli Prime Minister Ehud Olmert welcomed Syria's decision to participate.

"Israel sees as a positive development the participation of a high-ranking Syrian official in the meetings in Annapolis," said spokeswoman Miri Eisin, shortly after she arrived with Olmert in Washington. "The meetings are clearly about the Israeli-Palestinian process, but could be the beginning of new avenues to peace in the Middle East."

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

On the plane carrying her and Olmert to the U.S. for the conference, Livni had expressed confidence that Syria would attend the meeting, reasoning that a session on the search for a comprehensive Mideast peace offered the Syrians a forum to press their position on the Golan.

On the flight, Olmert restated his position that 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 the Jewish state's existence.

But Israeli officials have reported recent high-level talks between Israel and Damascus meant to sound out Syria on the prospect of resuming talks, which broke down in 2000.

Arab attendance at the Annapolis summit is seen as a victory for the U.S., which is hoping that broad Arab participation will help bring about an Israeli-Palestinian peace deal.

On the flight to Washington, Livni suggested that a lack of Arab backing contributed to the failure of the last round of Israeli-Palestinian peace 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 she also said that "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 the State Department will kick off on Monday with a dinner in Washington. They feared it would give Israel a public-relations boost while yielding the Palestinians little political benefit.

But they decided to come to the first large-scale Arab-Israeli gathering since a 1996 meeting in Egypt, 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 internally by the Islamic Hamas group's violent takeover of the Gaza Strip in June, which left him in control of the West Bank alone.

The Arab League has proposed a sweeping Mideast peace proposal that would offer 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 its 1948 creation.

Israel, which opposes a complete territorial pullback and the repatriation of Palestinian refugees to Israel, initially rejected the Arab proposal when Saudi Arabia first presented it in 2002. But over the past year Olmert has said it could be useful in new Israeli-Palestinian talks, and the Arab League re-energized the plan in March.

Meanwhile, Israeli and Palestinian delegations were making a last-ditch effort in Washington to nail down an elusive joint vision of where peace talks would head after this week's gathering.

The Palestinians want the joint statement to address, at least in general terms, the core issues at the heart of the conflict with Israel: final borders, conflicting claims to Jerusalem and the fate of Palestinian refugees.

Israel, however, wants a broader and vaguer statement that would allow more room for maneuvering. It says the haggling on these explosive issues should take place in the closed-door 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 his plane.

As he headed to the U.S. on Saturday, 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 a peace agreement in the coming year. Both Israel and the U.S. have said they hope to clinch a deal before the end of President George W. Bush's tenure in January 2009.

"We will exert all efforts to achieve peace within this period," Abbas said.

A high-placed Israeli official said attempts to forge a joint statement would continue in Washington. "We haven't given up yet," he said. He spoke on condition of anonymity because he was not authorized to discuss confidential talks.

Livni told reporters "there is no reason" such a statement shouldn't be issued, but quickly played down its significance by adding, "Naturally, this would be a statement that would launch the process but not resolve the conflict."