UNITED NATIONS (CNN) -- The ruling Hamas party will not join any Palestinian unity government that recognizes Israel, according to a spokesman for Palestinian Prime Minister Ismail Haniya.
"There will not be a national unity government if Hamas needs to recognize Israel," political adviser Ahmed Youssef said, according to Hamas sources.
His comments on Friday are in sharp contrast to those of President Mahmoud Abbas, who told the U.N. General Assembly the day before that any future government would recognize the Jewish state and renounce violence.
"These two letters contain mutual recognition between Israel and the PLO. They contain the renunciation of violence and the total commitment to negotiations as the past was reaching a permanent solution that will lead to the establishment of the state of Palestine alongside the state of Israel."
On Sunday, Palestinian negotiator Saeb Erakat said Abbas was suspending talks on a unity government with Hamas, the party that won parliamentary elections in January, until after he returned from the U.N. meeting in New York.
Erakat said Abbas was upset by Hamas' statements that it would not honor previously signed agreements with Israel.
Hamas has refused to recognize Israel's right to exist. It has been designated as a terrorist organization by the United States and the European Union, which cut off international aid to the Palestinian government after Hamas took control.
The unity government is seen as a bid to restore the money, which is the government's main source of funding.
On Wednesday, the so-called Mideast Quartet -- the United States, United Nations, EU and Russia -- said it welcomed Abbas' efforts to form a national unity government.
The quartet added that it hoped the platform between Hamas and Abbas' Fatah party would adhere to principles the group laid out this year -- recognizing Israel, renouncing violence and adhering to previous agreements.
Last week, U.S. Secretary of State Condoleezza Rice and Israeli Foreign Minister Tzipi Livni both indicated that the international community was unlikely to accept a Palestinian unity government unless it renounced terrorism and accepted Israeli's right to exist.