GAZA, Sept. 11 — The Palestinian Authority president, Mahmoud Abbas, said Monday that he had reached a tentative agreement with Hamas to form a national unity government in an attempt to end the Palestinians’ international isolation and the cutoff in Western assistance to their government.

In a speech on Palestinian television, Mr. Abbas said it would take several days to finish the deal, and provided no details of how his Fatah faction and the militant group Hamas, which leads the government, had resolved their considerable differences.

“We have finalized the elements of the political agenda of the national unity government,” Mr. Abbas said in his speech. “Hopefully, in the coming days we will begin forming the government of national unity.”

Details of the political agreement were believed to be limited to the unity government, rather than committing the Hamas movement more broadly to its terms. A national unity government will also have representatives of other Palestinian factions like Islamic Jihad and the Popular Front for the Liberation of Palestine, said Ghazi Hamad, the spokesman for the Hamas government.

“We’re trying to make a balance between the requirements of the international community and Palestinian factions,” Mr. Hamad said. “For everyone to sit at the same table won’t be easy, but we need to do this. We hope it will break the international siege and minimize the tensions on the street.”

Mr. Abbas’s intention in pressing to form this new government is to regain the funds that have been cut off to Hamas, by the West and by Israel, since it took office in late March.

Aides to Mr. Abbas said he hoped to be able to disband the current Hamas government within 48 hours, but that the two factions still disagreed over important portfolios. They are agreed that the current prime minister, Ismail Haniya of Hamas, will keep his job, and that Fatah will control the Finance Ministry. Fatah also wants the foreign minister’s post, but Hamas wants Mahmoud Zahar, a Hamas leader, to keep it. Hamas also wants to keep the Interior Ministry.

Officials said the new government would accept all previous Israeli-Palestinian agreements, an implicit recognition of a two-state solution. It would call for the negotiation of an independent Palestine outside of Israel’s 1967 borders, including Gaza, the West Bank and East Jerusalem, on the basis of an Arab League initiative.

The document is expected to recognize the Palestine Liberation Organization, which has signed all agreements with Israel, as the negotiating representative of the Palestinian people, and to acknowledge the right of Mr. Abbas to negotiate for the Palestinians.

After Hamas formed the government, which Fatah initially refused to join, the United States and the European Union took steps to halt aid to the Palestinian Authority that constitutes part of the authority’s budget, and Israel stopped handing over the $50 million a month in taxes and customs receipts collected on behalf of the Palestinians, a major reason for the Palestinian deficit.

All said that the government of Hamas, which they have considered a terrorist group, must first recognize the right of Israel to exist, forswear violence and accept previous Israeli-Palestinian agreements.

Since Hamas gained control of the government in March, the 165,000 employees of the Palestinian Authority have received less than two months of their salaries, causing considerable hardship and a collapse of the economy, especially in Gaza. Crossings into Israel from Gaza have been regularly closed, which Israel said was a result of security threats.

It is not known whether the unpublished program of the unfinished new government will be enough for Israel to hand over funds that now total more than $350 million. The European Union has already suggested, though not explicitly, that it will resume contacts and aid to a unity government, and the United States, which does not give direct budget support, has been wary, but its view will be important in the Israeli decision.

Ziad Abu Amr, a lawmaker and mediator in the negotiations, said that if a new government did not permit the resumption of funds transfers and aid, “there’s not much point to the whole exercise.”

The Israeli Foreign Ministry spokesman, Mark Regev, said that if a new Palestinian government accepted the three international conditions “and releases Gilad Shalit,” a captured Israeli soldier, “that would create a new momentum in the peace process and put us firmly on the right track.”

But he added, “Anything short of that would unfortunately lead to more stagnation that is not good for Israel, not good for the Palestinians and not good for anyone who wants peace in the Middle East.”

The Israeli foreign minister, Tzipi Livni, told Israel radio that if the new government did not meet international conditions, and if Mr. Abbas “decides not to take a step in this direction, but rather join something which actually means he is joining a Hamas-led government of terror, then I’m afraid we are going to have a problem.”

Hamas has moved a long distance, said Mr. Hamad, the Hamas government spokesman, adding, “No one should push them into a corner.”

Hamas recognizes the fact of Israel but refuses to recognize its right to exist, a position repeated Monday by a Hamas spokesman, Sami Abu Zuhri, when he said: “Hamas will still have its political agenda. We will never recognize the legitimacy of the occupation.” That term lets Hamas be vague at different moments about whether it means the occupation of land captured during the 1967 war, or, as its charter insists, Israel’s very existence in the region.

But Mr. Hamad points out that the charter of Israel’s conservative Likud Party calls for an Israel on both banks of the Jordan River, even as Likud governments have recognized the Oslo peace agreements of more than a decade ago and a two-state solution.

Since Fatah and Hamas agreed in principle on a national unity government in June, Mr. Abbas has made several statements indicating that a deal was close. He put major questions to Mr. Haniya 10 days ago, and reportedly threatened to dismiss the current government if it did not agree to work with Fatah to end the international aid freeze for the benefit of Palestinians in general.

Fatah says it is prepared to negotiate with Israel, and seeks a Palestinian state based on Israel’s 1967 borders, which would include all of the West Bank and the Gaza Strip, with a capital in East Jerusalem. Hamas says that all the land in the region belongs to Muslims, but has said it would consider a long-term truce with Israel if a Palestinian state were established based on the 1967 borders.

Broke and isolated, largely because of Israeli and American policy, the Hamas government has been ineffective since coming to power in March. Many Palestinian teachers went on strike at the beginning of the school year in early September. On Monday, Mr. Abbas called for the strike to end.

“We call for a return to work and the end of the strike because all the sons of the Palestinian people should unite in the national interest,” he said.

Steven Erlanger reported from Gaza, and Greg Myre from Jerusalem.