An Israeli delegation left talks in Cairo to pause the Israel-Hamas war on Tuesday, Israeli and US media reported.
Israeli intelligence chief David Barnea met CIA Director William Burns in the Egyptian capital for talks on a Qatari-brokered plan to temporarily halt fighting in Gaza.
The negotiations, which also involved Qatar's prime minister and Egyptian officials, were part of an intensifying effort to secure a ceasefire before Israel proceeds with a full-scale ground incursion into the southern city of Rafah, where more than half of the territory's population has fled.
Foreign governments and the United Nations have voiced increasingly frantic alarm about the possible civilian toll of such an assault, while Israel has vowed to press ahead with its campaign until it successfully eradicates Hamas from all of Gaza, including Rafah.
The Israeli delegation was on its way back from Cairo on Tuesday night, an official in the Prime Minister’s Office told The Times of Israel.
The Wall Street Journal, citing Egyptian officials, said Barnea's delegation had departed the Egyptian capital "without closing any of the major gaps in the negotiations".
The talks will continue for another three days, according to Egyptian state-owned television channel Al Qahera, citing a senior Egyptian official.
The same official said the talks had been mostly "positive", the television channel reported.
A Hamas source told AFP that a member of the group's political bureau would head a delegation to Cairo to meet the Egyptian and Qatari intelligence chiefs.
National Security Council spokesman John Kirby called the negotiations "constructive and moving in the right direction".
"Nothing is done until it is all done," he told reporters at the White House.
Ahead of the efforts to hammer out a truce, the Israeli campaign group Hostages and Missing Families Forum sent the Mossad chief a plea saying the delegation must "not return without a deal".
About 130 of the 250 hostages taken by Hamas during the October 7 attack are still believed to be in Gaza. Israel says 29 of them are presumed dead.
The Hamas attack that launched the war resulted in the deaths of about 1,160 people in Israel, mostly civilians, according to an AFP tally based on official Israeli figures.
At least 28,473 people, mostly women and children, have been killed in Israel's relentless bombardment and ground offensive in Hamas-run Gaza since then, according to the health ministry in the Palestinian territory.