Palestinian Authority Chairman Mahmoud Abbas is planning to appoint new security chiefs in a bid to maintain control over PA security forces after Hamas forms the new cabinet, PA officials said Monday. The revelation came as Abbas met with Hamas leader Ismail Haniyeh in Gaza City and asked him to form the cabinet. Haniyeh heads Hamas's Change and Reform List, the largest faction in parliament. Sources close to Hamas said a formal request to Haniyeh would be delivered Tuesday. According to the officials, Abbas had already decided on two security appointments. They said Rashid Abu Shabak, commander of the Preventive Security Force in the Gaza Strip, would be named overall commander of internal security. Sakher Bsaisso, a top Fatah official from the Gaza Strip, was expected to be appointed commander of the crossing points and borders. "President Abbas is planning to appoint new heads to other security forces," one official told The Jerusalem Post. "The Palestinian security forces remain under his power and this is his prerogative." Another official said Abbas's move was designed to "create new facts on the ground" before Hamas completed the formation of its cabinet. "If Hamas thinks that we're going to give them control over the security forces, they are mistaken," he said. "President Abbas will remain the commander-in-chief of all the security forces." Many PA security commanders are worried that Hamas might try to take control of the security forces. In meetings with Abbas over the past few weeks, the security commanders - who are all members of Fatah - announced that they would not allow Hamas to interfere with their work. Earlier Monday, Hamas presented Haniyeh as its choice for Palestinian prime minister in a meeting with Abbas, a Hamas official said. Mahmoud Zahar, a leader of the Islamic terror group that swept last month's parliamentary election, said Abbas would present Haniyeh with his official letter of appointment Tuesday evening, setting in motion the process of forming a new government that would be approved by the Hamas-dominated parliament. Talking to reporters after the meeting, Haniyeh said he would try to form a joint government with Fatah, the ruling party Hamas trounced in the election, "that can shoulder its responsibilities in the political area and internal issues." So far Fatah has refused to join. Meanwhile, the Popular Front for the Liberation of Palestine (PFLP) became the first Palestinian group to agree to join a Hamas-led cabinet. The Islamic Jihad organization, on the other hand, rejected Hamas's invitation to join the new coalition. PFLP representative Rabah Muhanna said after meeting Hamas officials in Gaza City that his group had agreed "in principle" to join the coalition. "We have given our agreement in principle to participating in the government as long as we can reach an accord on the political and social program," he said. Also on Monday, Haniyeh criticized Israel for freezing the transfer of tax money. "The Israelis are trying to starve innocent people by taking money from our taxes, and we are going to fight this by all legal means," Haniyeh said. "This collective punishment will not break the determination of the Palestinian people."