Updated

As Israeli and Palestinian officials on Sunday wrapped up preparations for this week's U.S.-sponsored Mideast peace conference, Palestinian President Mahmoud Abbas promised to "exert all efforts" to reach a deal with Israel, but acknowledged that negotiations on a joint statement ahead of the summit are in trouble.

Israel and the Palestinians have been trying for months to hammer out a joint blueprint for peace to present to the conference, taking place this week in Washington and Annapolis, Maryland. But Abbas said that significant differences remain.

"The positions with the Israelis before Annapolis are still far apart, and the negotiations are still ongoing," Abbas said on his plane before arriving in the U.S. His quotes appeared 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 reach a deal before President George W. Bush leaves office in January 2009.

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

Negotiations on the pre-summit declaration have deadlocked over whether the document should address the core issues of an agreement: final borders between Israel and a future Palestinian state, a resolution to disputed claims to Jerusalem; and the fate of Palestinians who became refugees following Israel's establishment in 1948.

The Palestinians want the document to address these core issues in general terms. Israel wants much vaguer language, though Prime Minister Ehud Olmert has promised to open negotiations on all areas of dispute after the Annapolis summit. It remained unclear whether the sides would bridge their differences before the conference, which is scheduled to begin Monday in Washington.

In the interview, Abbas urged a skeptical Palestinian public to give the conference a chance. "We have to start and to look at the glass as half full, not halt empty," he said. "We have to wait and see the results of Annapolis. We must not judge the conference before it starts."

At the conference, Bush wants the Israeli and Palestinian leaders to declare a formal resumption of peace talks, which broke down in violence seven years ago. He also is seeking to counter Iran's growing influence in the region. Iran was not invited.

In a boost for Bush, Saudi Arabia and 14 other Arab states agreed last week to attend the conference. Saudi Arabia's participation is especially important, both because of its influence throughout the Arab world and because it does not have diplomatic relations with Israel.

Syria, a key adversary of Israel, announced Sunday that it would also attend in a move welcomed by Israeli officials.

Abbas praised the decision by Arab countries to come to Annapolis. "This shows that the Arab position is unified more than ever on the Palestinian cause," he said.

While Abbas enjoys widespread backing from the international community, he faces deep divisions at home with his bitter rival, Hamas, in control of the Gaza Strip.

The Islamic militant group took over Gaza in June after routing Abbas' forces there. Abbas now leads a pro-Western government from the West Bank. Abbas' lack of control in Gaza has raised questions about his ability to implement any future peace deal there.

Abbas said opposition to his peace moves is "legitimate," but said "we are facing a historic and important opportunity and we must use this opportunity."

Hamas said Saturday it was shocked that Arab countries have decided to attend the peace summit and was close to developing a more lethal rocket to fire into Israel.

Israel has repeatedly said it expects Hamas to try and thwart peace efforts. Gaza militants have fired hundreds of crude, homemade rockets at Israeli border communities in recent years, killing 12 people.

Hamas, along with smaller Palestinian opposition groups, have scheduled a series of protests in the coming days to counter the Annapolis conference.

Several thousand women joined an anti-summit demonstration in Gaza City organized by Hamas, where they waved copies of the Quran and carried pictures of Hamas leader Ismail Haniyeh.

"Wake up, Israel doesn't know peace," the crowd chanted. "The enemy only knows the language of force."

Hamas lawmaker Mushir al-Masri said the gathering was sending a message to the Palestinian negotiators. "You are not delegated from the people. Any results from Annapolis will not be recognized by the Palestinian people," he told the crowd.

While promoting talks with Abbas' government in the West Bank, Israel continues to battle Palestinian militants in the West Bank and Gaza.

At around noon Sunday, a team of Israeli special forces killed a wanted Palestinian militant in the West Bank town of Tulkarem, Palestinians and the army said. The troops wounded a second militant and took him to an Israeli hospital for treatment, the military said.

In the Gaza Strip, Israeli tanks and infantrymen killed two Palestinian militants early Sunday, the army and Palestinian officials said.