Mr. Abbas “basically miscalculated,” said Hillel Frisch, a professor at Israel’s Bar-Ilan University who specializes in Palestinian politics and the Israeli-Palestinian conflict. “They were both in it to appease the Americans, and wanted to blame each other for the failure of the talks. By moving with Hamas, they played into Israeli hands.”

After the reconciliation deal drew harsh reactions from Israel and Washington, Palestinian leaders had sought on Thursday to soften its impact on the peace process. Jibril Rajoub, a top official in Mr. Abbas’s Fatah faction, said that the new government would recognize Israel and renounce violence, meeting the conditions set by the “Quartet” of Middle East peacemakers —the United States, United Nations, Russia and the European Union —that Hamas has repeatedly rejected.

“The government of national consent that will be established, headed by Abu Mazen, will declare clearly and unequivocally that it accepts the Quartet’s conditions,” Mr. Rajoub said, using Mr. Abbas’s nickname in an interview on Israel’s Army Radio channel. “There is no cause for concern.”

Similarly, Yasser Abed Rabbo, secretary of the P.L.O. executive committee, called Wednesday’s agreement “merely a first step” and said that American and Israeli reactions were “premature.”

For its part, Hamas signaled that it was drawing a distinction between its own views and those of the unity government it was joining and that there was no need for Hamas to recognize Israel.

“You don’t need organizations to recognize Israel,” Ghazi Hamad, the Hamas deputy foreign minister, told Ynet, an Israeli news website. “It’s enough that the Palestine Liberation Organization — the representative of the Palestinian people — recognizes the State of Israel.” As for whether his party would renounce violence, Mr.Hamad told Ynet that the question would be worked out in negotiations with Fatah over the next few weeks.

Several Palestinian officials and analysts emphasized that the promised new government was to be made up of “technocrats” — professionals who are not partisan political figures — and that its task was to unify the Gaza Strip and West Bank after a seven-year schism and prepare for elections to be held in six months. Therefore, they said, there was no contradiction between a reconciliation between Fatah and Hamas, and the Palestinian government’s continued negotiation with Israel.