Ismail Haniya, the prime minister of the Islamist Hamas movement in power in the Gaza Strip, said on Saturday he was "ready to resign."
"I am prepared to tender my resignation as part of the reconciliation agreement between Hamas and Fatah," the secular party of Palestinian Authority (PA) president Mahmud Abbas.
"This agreement is very important and should boost efforts to end the divisions and encourage unity among Palestinians," he added.
On Wednesday, the rival Palestinian groups reached an "understanding" in Cairo to set up a transitional unity government and hold elections.
Egypt, which shares a border with Gaza, has tried to bring the two sides together since Hamas defeated Fatah loyalists in week-long street battles four years ago, reducing their power base to the Israeli-occupied West Bank.
The PA prime minister, Salam Fayyad, expressed the hope on Wednesday that the agreement could lead to "the reunification of the nation, needed to enable our people to decide their destiny and to establish an independent state on all territories occupied since 1967, with east Jerusalem as its capital."
The Palestinian factions were on the verge of agreeing a deal in 2009 that would have led to a transitional government ahead of elections when Hamas pulled out.