The deal would also see both Hamas and Fatah form an interim government before elections.
Fatah's Palestinian Authority President Mahmoud Abbas told reporters that he welcomed the agreement.
The meetings in Cairo are centred around implementing the 2011 Cairo Agreement between the two political parties, in hopes of ending the 10-year political schism.
According to a readout of a telephone call issued by a United Nations spokesperson, Mr. Guterres said he was encouraged by the recent progress in allowing the Palestinian Government to take up its responsibilities in Gaza and welcomed Egypt's efforts to achieve this goal.
According to one Palestinian official, Abbas may soon visit the blockaded Gaza Strip - for the first time in ten years - in light of the diplomatic success in Cairo.
The official was referring to the diplomatic Quartet on Middle East peace, which includes the United Nations, the United States, the European Union and Russian Federation. Hamas and Fatah organisations began negotiations on reconciliation last Tuesday through Egypt.
The U.S. says it wants the Palestinian Authority to take control of Gaza again.
Saleh al-Arouri, deputy head of Hamas's influential Political Bureau, also voiced appreciation for the role played by Egypt in sponsoring inter-Palestinian dialogue.
There was no indication that an understanding had been reached on the fate of Hamas's armed wing, a sticking point which analysts have said could yet scupper reconciliation efforts.
"Israel will examine developments in the field and act accordingly", said a statement from Prime Minister Benjamin Netanyahu's office.