WASHINGTON, Nov 4, 2023 (BSS/AFP) - Talks are being held on a "very significant" pause in the Middle East conflict to win the release of dozens of hostages taken by Palestinian militant group Hamas, a senior White House official said Friday.

"It is something that is under a very serious and active discussion. But there is no agreement as of yet to actually get this done," the official said, as fighting between US ally Israel and Hamas raged in the Gaza Strip.

An estimated 240 Israeli and foreign hostages were kidnapped by Hamas during its October 7 assault on Israel in which militants killed more than 1,400 people, mostly civilians, according to Israeli officials.

The health ministry in Hamas-run Gaza says more than 9,200 people been killed in relentless Israeli bombardments since then, mostly women and children.

The US official, who spoke on condition of anonymity, said "nobody knows" the exact number of hostages, adding that it was "well over 100 and maybe over 200."

To get that many people out "is going to require a fairly significant pause in hostilities."

But the official warned: "There's absolutely no guarantee a) that is going to happen or b) when it's going to happen."

Both Israel and the United States have previously ruled out a blanket ceasefire, which they say would allow Hamas to regroup and resupply, but US President Joe Biden has backed "temporary, localized" pauses.

At a fundraiser earlier this week, he said: "I think we need a pause. A pause means giving time to get the prisoners out."

Israeli Prime Minister Benjamin Netanyahu, however, has warned that there could be no "temporary truce" in Gaza unless Hamas releases the hostages.

The official said Washington was in constant dialogue with Israel, "asking hard questions" on points such as "the objectives you're seeking, and an honest assessment of whether you're achieving them."

The Israelis "have significantly refined what originally was their plan," the official said, without elaborating.

As for allowing Palestinian civilians, particularly those with foreign passports, to leave the Gaza Strip amid Israel's bombardment, the official said Hamas provided a list of wounded Palestinians for evacuation with one-third of the names those of Hamas members and fighters.

"That was just unacceptable to Egypt, to us, to Israel," the official said, explaining the delay in opening the Rafah border crossing with Egypt in southern Gaza.