Israeli Prime Minister Benjamin Netanyahu was due to hold consultations with security chiefs and ministers on Friday after an Israeli delegation returned from Cairo with no agreement on extending the Gaza ceasefire, two Israeli officials said.
Egyptian and Qatari mediators asked for some time over the next few days to resolve the crisis over the ceasefire, which is due to expire on Saturday, the officials said.
However, Israel and Hamas remain far apart on key issues and each has accused the other of violating the ceasefire, casting doubt over the second phase of the deal meant to include releases of additional hostages and prisoners as well as steps toward a permanent end of the war.
There is no sign of agreement, either among or between Israelis and Palestinians, or between Western and Arab governments, over Gaza's future. That uncertainty is complicating efforts to negotiate a lasting resolution.
Israeli officials have previously said Israel was ready to resume fighting in Gaza if its hostages are not returned.
Hamas called on Friday for the international community to press Israel to immediately enter the second phase without delay. It is unclear what will happen if the first phase ends on Saturday without a deal.
A senior official of the Palestinian Authority, State Minister of Foreign Affairs Varsen Aghabekian, also said on Friday that she would like the ceasefire phases to move ahead as originally planned.
"I doubt anyone in Gaza will want to go back to war," she said in Geneva.
The Cairo talks are being mediated by Egypt and Qatar with U.S. support. U.S. President Donald Trump said on Thursday there were "pretty good talks going on".
Asked whether the ceasefire deal would move into the second phase, Trump said: "Nobody really knows, but we'll see what happens".
The Gaza war is the latest confrontation in decades of conflict between Israel and Palestinians.
It began on Oct. 7, 2023, when fighters from the Islamist group Hamas stormed border defences from Gaza and attacked Israeli communities, killing around 1,200 people and seizing 251 hostages, according to Israeli tallies.
The Israeli military campaign in retaliation has killed more than 48,000 people, according to Palestinian authorities, while destroying large swathes of the tiny, crowded territory and leaving most of its 2 million inhabitants homeless.
CEASEFIRE
The ceasefire has mostly held during its first six weeks, although both sides have accused each other of breaches, particularly in the treatment of Israeli hostages and Palestinian detainees, and in the handling of releases.
The United Nations has described images of both emaciated Israeli hostages and released Palestinian detainees as distressing, saying they reflected the dire conditions in which they were held.
Hamas has staged shows of strength during hostage releases, parading them in front of cameras. Israeli authorities have made released detainees wear clothes bearing pro-Israeli slogans.
Israel is now negotiating to extend the first phase of the ceasefire deal by 42 days, according to the Egyptian security sources.
Israeli government officials said earlier this week that Israel would attempt to extend the initial phase with Hamas freeing three hostages a week in return for the release of Palestinian detainees.
Discussions on an end to the war are complicated by the lack of any agreement over basic questions such as how Gaza would be governed, how its security would be managed, how it could be rebuilt, and who would pay for that.
Trump proposed this month that the U.S. should take over Gaza and redevelop it as a "Riviera of the Middle East" with its population displaced into Egypt and Jordan.
Arab countries have rejected that idea but have yet to announce their own plan.
European countries have also rejected the displacement of Palestinians and say they still support a two-state solution to the conflict.
