Palestinian President Mahmoud Abbas and Palestinian factions met in Egypt to hold unity talks on Saturday.
The Palestinian news agency said that as well as chairing Sunday's meeting of the heads of Palestinian factions, Abbas "is scheduled to meet with his Egyptian counterpart Abdel Fattah el-Sissi."
Last week, Islamic Jihad leader Ziyad al-Nakhalah made his group's participation in the talks conditional on releasing its members and those of other factions detained by Palestinian security forces in the West Bank.
In a statement to Agence France-Presse (AFP) Saturday, Islamic Jihad official Mohammad al-Hindi again denounced "continued political detention and prosecution of the resistance."
The Popular Front for the Liberation of Palestine is also boycotting the talks.
Sunday's meeting will include the heads of other political factions, including Hamas leader Ismail Haniyeh.
Both Abbas and Haniyeh met in Ankara on Wednesday in the run-up to Sunday's crucial meeting. Turkish President Recep Tayyip Erdoğan, who has good relations with both, hosted the talks and said his government would do its best to push for intra-Palestinian reconciliation.
A Palestinian official, speaking to AFP on condition of anonymity because they are not authorized to speak to the media, said the talks aim to "end the divisions (between factions) in preparation for a unified Palestinian government and presidential and general elections."
Haniyeh's spokesman Taher al-Nunu told AFP that Hamas sought to "unify the Palestinian position" under a strategic plan to "confront the Israeli occupation in light of the aggression of its extremist government."
Since Hamas took control of the Gaza Strip in 2007, the movement has been at loggerheads with Abbas's secular Fatah, which administers Palestinian-run areas of the West Bank, which Israel occupied in the 1967 Six-Day War.
Attempts to end the more than 15-year Fatah-Hamas rift saw leading figures from both movements sign a reconciliation deal in Algiers last year, promising long-delayed Palestinian elections in 2023.
Egypt's meeting comes amid a resurgence of violence linked to the Israeli-Palestinian conflict, which this year has killed at least 203 Palestinians, 27 Israelis, one Ukrainian and one Italian, according to an AFP tally compiled from official sources from both sides.
