They headed to Cairo upon an official Egyptian invitation to hold a comprehensive dialogue that leads to ending up more than ten years of internal division between the two groups.
"Unity and national reconciliation among all our Palestinian people is our strategic option to move forwards".
A Fatah official in Cairo, Samih Barzaq, told Asharq Al-Awsat that the "unprecedented" measures taken by the PA against Gaza employees will be lifted "very soon".
The two sides remain sharply at odds, however, over the future of Hamas's 25,000-strong armed wing, which the terror group says is nonnegotiable.
Meanwhile, Hamas leader Ismail Haniyeh said the weapons of the "resistance" - referring to the terror group's army - would not be given up until the conflict with Israel is ended. Hamas said that point was not up for discussion.
Representatives from both sides voiced optimism ahead of the talks being held behind closed doors.
While acknowledging that the issue of the employees was an "obstacle", Ahmad said it would be "solved within four months".
The Palestinian cabinet travelled to Gaza last week to assume control over government offices. In August, a suicide bomber allegedly linked to the Islamic State group killed a Hamas guard in southern Gaza along the border with Egypt, in a rare attack against the Islamists.
After dissolving the committee, Abbas instructed last week to send Rami Hamdallah, the prime minister of the Palestinian consensus government, his cabinet and Palestinian security chiefs to Gaza to hand over ruling Gaza.
The sources said that after that they will go back to the Palestinian territories and wait for another Egyptian invitation for a wider dialogue that will include leaders of other Palestinian factions and political powers.
Al Jazeera's Harry Fawcett reports from Ramallah, the occupied West Bank.