DAMASCUS, Syria - Palestinian President Mahmoud Abbas and Hamas' exiled chief failed to resolve an increasingly bitter dispute and form a unity government, dashing hopes for a quick end to the political crisis.

Officials from both sides said Monday after the late night meeting a day earlier that the main sticking point was the wording of the official document declaring the new government's program.

Abbas wants it to read that the government will "abide by'' Arab League summit resolutions and previous agreements signed between Israel and the Palestinians. Hamas insists on using the word "respect,'' which falls short of international and Israeli demands that Hamas uphold all earlier accords.

The deputy head of Hamas' politburo Moussa Abu Marzouk confirmed Monday that the so-called letter of designation that Abbas would give a new prime minister was still a topic of discussion.

"But these are not just words ... they have (political) implications,'' he told The Associated Press.

He accused Fatah of backtracking on formulas already agreed on in the past. "The other side changed its position. They (Fatah) want to implement only what's convenient for them,'' he said.

A Hamas spokesman in Gaza, Salah Bardawil, said "abiding by means recognizing Israel, and that's a free gift to Israel.''

"If the argument is we must deal with the reality before us, we say, let's respect those agreements, and not become completely entangled in the mistakes of the past,'' he added.

A joint statement issued by Abbas and Mashaal following their meeting on Sunday _ the first since July 2005 _ said the two sides "achieved major progress'' and pledged to continue talks on forming a coalition government within the next two weeks.

"There are still points of disagreement, but we will try to resolve them through a national dialogue until we form a national unity government,'' Mashaal said during a press conference with Abbas in the Syrian capital.

The two sides stressed that Palestinian infighting, which has killed at least 35 people in recent fighting, was unacceptable and pledged to try to avoid political friction that has been sparking the violence.

"Palestinian bloodshed was considered totally prohibited, and we must exert all efforts to avoid friction and internal clashes,'' Abbas said.

Both sides also reiterated their rejection of an Israeli proposal for a transitional Palestinian state with temporary borders.

There had been hopes that the Abbas-Mashaal meeting would make headway in forming the unity government and end months of deadly violence in the West Bank and Gaza Strip.

Hamas swept to power in elections last year and controls the Palestinian parliament and cabinet, but it is labelled by the United States as a terrorist group. Its refusal to recognize Israel's right to exist led to western sanctions that have paralyzed the Palestinian economy. Abbas, who leads the mainstream Fatah party and is widely seen as a moderate, was elected president separately.

Syria hosts the exiled leadership of a number of Palestinian militant groups _ among them Mashaal, who has lived in Damascus since 1997, when he survived an Israeli assassination attempt in Jordan.

Abbas has been pushing Hamas for months to form a unity government of independent experts in hopes of ending the sanctions and has threatened to call early elections if the two sides can't agree.

In the Hamas stronghold of Gaza _ where tensions between the two factions frequently have exploded into open warfare _ Palestinian Prime Minister Ismail Haniyeh, of Hamas, downplayed the significance of the Abbas-Mashaal meeting and said representatives from the two sides would meet on Tuesday in Gaza to continue the dialogue.