"We are ready for a total ceasefire in the occupied territories and in Israel, in line with the road map [peace plan]," the group's 129-member revolutionary council said in a statement on Sunday.
But Fatah also stressed "the Palestinians' right to self defence against attacks by the Israeli army", and their "right to resist the occupation, settlement and the construction" by Israel of a West Bank separation barrier.
Violence has dropped in recent weeks in Israel, the West Bank and Gaza amid Abbas' efforts to bring various Palestinian groups into a truce they say must be reciprocated by the Israeli army.
Israel and the Palestinians have said they hope to declare a formal halt to more than four years of violence at a summit in Sharm al-Shaikh.
Abbas, Israeli Prime Minister Ariel Sharon, Egyptian President Husni Mubarak and Jordan's King Abd Allah are expected to convene the summit.
US Secretary of State Condoleezza Rice, in the region in a new US diplomatic bid, praised Abbas' administration in remarks to reporters in Jerusalem.
She said it now appeared possible "to get back onto the road map", a UN, US, EU and Russian-backed peace plan stalled by violence.
Rice was to meet Abbas in the West Bank town of Ram Allah on Monday.
In addition to the ceasefire call, the 25 members of Fatah's higher committee, which conducts the group's daily affairs, tendered their resignations in a bid to pressure the movement to bring forward an internal election planned for August.
Fatah, founded by the late Yasir Arafat, has not held elections since 1989.