Negotiators have been trying to hammer out the final details of a ceasefire in Gaza after marathon talks in Qatar, and US and Egyptian leaders promised to stay in close contact about a deal in the coming hours.
More than eight hours of talks in Doha had fuelled optimism.
Officials from mediators Qatar, Egypt and the US as well as Israel and Hamas said an agreement for a truce in the besieged enclave and release of hostages was closer than ever.
Talks on the last details of a Israel-Hamas ceasefire were under way, Qatar said. (AP PHOTO)
But a senior Hamas official told Reuters late on Tuesday the Palestinian group had not responded because it was waiting for Israel to submit maps showing how its forces would withdraw from Gaza.
Qatar's foreign ministry spokesperson Majed Al-Ansari earlier told a news conference that both sides were presented with a text and talks on the last details were under way.
US President Joe Biden, whose administration has been taking part alongside an envoy of President-elect Donald Trump, said a deal was close after the war decimated Gaza, killed tens of thousands of people and triggered conflicts in the region.
Biden and Egyptian President Abdel Fattah El-Sisi talked about progress in the negotiations on Tuesday.
"Both leaders committed to remain in close co-ordination directly and through their teams over the coming hours," the White House said.
The presidents "emphasised the urgent need for a deal to be implemented".
Hamas said the talks had reached the final steps and it hoped this round of negotiations would lead to a deal.
The UN said it was preparing to expand humanitarian assistance to Gaza under a ceasefire deal. (AP PHOTO)
An Israeli official said talks had reached a critical phase although some details needed to be worked out: "We are close, we are not there yet."
Visiting Rome, Israeli Foreign Minister Gideon Saar said on Tuesday he believed a majority of Israel's coalition government would support a Gaza deal if one was agreed, despite vocal opposition from hardline nationalist parties in the coalition.
Militant group Islamic Jihad, which also holds hostages in Gaza, said it was sending a delegation to Doha to take part in the final stage of talks.
If successful, the phased ceasefire - capping more than a year of start-and-stop talks - could halt fighting that has decimated Gaza, killed tens of thousands of Palestinians, made most of the enclave's population homeless and is still killing dozens a day.
That in turn could ease tensions across the wider Middle East, where the war has fuelled conflict in the West Bank, Lebanon, Syria, Yemen and Iraq, and raised fears of all-out war between Israel and Iran.
Israel would recover about 100 remaining hostages and bodies from among those captured in the October 7, 2023, attacks by Hamas that precipitated the war. In return, it would free Palestinian detainees.
US Secretary of State Antony Blinken, who gave a speech in Washington outlining a vision for governing the Palestinian territories after the war, said it was up to Hamas to accept a deal that was already set for implementation.
Israel would get about 100 remaining hostages and bodies from among those captured under the deal. (AP PHOTO)
Despite the efforts to reach a ceasefire, the Israeli military, the Shin Bet internal intelligence agency and the air force attacked about 50 "terrorist" targets throughout Gaza in the past 24 hours, according to Shin Bet and the military.
The United Nations said it was preparing to expand humanitarian assistance to Gaza under a potential ceasefire but uncertainty around border access and security remained obstacles.
An Israeli official said the deal's first stage would include the release of 33 hostages, including children, women including some female soldiers, men above 50, and the wounded and sick.
Israel would gradually and partially withdraw some forces.
A Palestinian source said Israel would free 1000 Palestinian prisoners in the first phase over 60 days.
Israel launched its assault in Gaza after Hamas-led fighters stormed across its borders on October 7, 2023, killing 1200 people and taking more than 250 hostages, according to Israeli tallies.
Since then, Israeli forces have killed more than 46,000 Palestinians in Gaza, according to Palestinian health officials.