Mediators expected to reconvene in Cairo as soon as Sunday are searching for a formula acceptable to Israel and Hamas to unlock a lasting ceasefire in Gaza, four sources with knowledge of talks said, as pressure mounts ahead of Ramadan for a pause in fighting.
Israeli and Hamas delegations were expected to arrive in Cairo on Sunday, two Egyptian security sources said, though another source briefed on the talks said Israel would not send a delegation until it got a full list of hostages who are still alive.
Hopes for the first pause in fighting since November had risen this week after a previous round of talks mediated by Qatar and Egypt in Doha and indications from US President Joe Biden that agreement was close.
Hamas has not backed away from its position that a temporary truce must be the start of a process towards ending the war altogether, the Egyptian sources and a Hamas official said.
However, the Egyptian sources said assurances had been offered to Hamas that the terms of a permanent ceasefire would be worked out in second and third phases of the deal. The duration of the initial pause, a phase expected to last about six weeks, had been agreed upon, the sources said.
Hamas did not immediately respond to a request for comment regarding the assurances and whether they were sufficient to move forward with the six-week pause.
"When it comes to ending the war and pulling out forces out of Gaza, gaps remain unbridged," a Palestinian official familiar with mediation efforts said. The official did not immediately confirm the Cairo talks.
A senior US administration official said on Saturday that the framework for a six-week pause was in place, with Israel's agreement, and now depended on Hamas agreeing to release hostages it has held in Gaza since its attacks on southern Israel on Oct. 7.
For its part, Israel will not take part in more talks until Hamas clarifies the number of hostages slated to go free, and how many are still alive, the source briefed on the talks said.
Hamas said this week that in total around 70 captives had been killed due to Israel's military operations.
Israel also wants Hamas to agree to a ratio of Palestinian prisoners to be released in exchange for each hostage, said the source, who declined to be identified further.
A draft proposal made in Paris in February and sent to Hamas this week indicated progress on a number of issues and proposed an overall ratio of 10 Palestinian prisoners held in Israel for each hostage.
"No delegation will be going to Cairo until Hamas provides answers," the source said.
Completion of a truce deal also required an agreement on the pullback of Israeli forces from northern Gaza and a return of residents displaced towards the south of the coastal enclave, the Egyptian sources said, although the source briefed on the talks said that for Israel the return of displaced Palestinians to northern Gaza was not the main holdup.
The draft proposal also included a commitment to boost humanitarian aid to the enclave, suffering crippling shortages of food and medicine and where more than a million people have been displaced from their homes.
It was unclear if an incident on Thursday in which scores of Palestinians were killed as people waited for aid near Gaza City in the north could affect the timing of any deal.
Speaking to reporters about a ceasefire as he left the White House on Friday, Biden said: "We're not there yet."
Nevertheless, the security sources said Egyptian and US negotiators were still confident a partial or complete agreement will be reached by the middle of next week.
Israel, Hamas, Egypt, Qatar, and the US State Department did not immediately respond to requests for comment.
Pressure on Hamas to reach deal
After five months of war, Hamas is also under pressure to reach a deal, the US official and one diplomat in the region said.
Israel's military campaign began in response to the Hamas attack on Oct. 7 that killed 1,200 people and involved the seizure of 253 hostages, according to Israeli tallies.
The war has caused an unprecedented humanitarian crisis, with donor nations turning to air drops of food after aid flows into Gaza dwindled in recent days, UN officials say.
This week, the number of Palestinians killed in Gaza since Oct. 7 passed 30,000, Hamas-controlled health authorities in the enclave said.
Some Palestinians have been calling on social media for Hamas to agree to a pause that could allow bakeries to reopen and displaced people to return to their homes in northern Gaza for Ramadan, when Muslims fast until dusk.
Biden's comments about an imminent deal were received with some hope by the people in Gaza, adding to the pressure on Hamas to accept a deal that could lead to a permanent ceasefire, the diplomat in the region said.
"At the end of the day Hamas wants a truce, but wants a permanent ceasefire more, they are not an army in the full military sense and they don't have access to foreign arms supplies and sooner or later they will start running out of the gun power," the diplomat said.
The United States had been pushing for the six-week truce in the hope that it would be hard for Israel to restart military operations after that, a US official said.
Israel has said it is ready to accept a temporary halt to fighting during a hostage-and-prisoner swap, but Israeli Prime Minister Benjamin Netanyahu has said the military campaign should continue until it achieves "total victory" over Hamas, followed by open-ended Israeli security control over Gaza.
The Egyptian security sources said mediators had raised options for winning Israel over to a permanent ceasefire deal including approval of a security buffer zone between Israel and the Gaza Strip, and arrangements for Israel to jointly monitor Egypt's border with Gaza.
Egypt's Foreign Minister Sameh Shoukry said on Friday Egypt was hopeful that a cessation of hostilities could be agreed before Ramadan, which is expected to begin on March 10 or March 11.