WASHINGTON, United States - US President Joe Biden's Middle East envoy held talks in the region Tuesday as hopes rose for a new deal to free Israeli hostages held by Hamas in exchange for a longer pause in fighting in Gaza.

The White House said it would support a pause that was longer than the week-long halt in November, as it confirmed that Brett McGurk was in Egypt for discussions and would visit other key countries.

The announcement comes after US news site Axios said Israel had proposed to Hamas, via Qatari and Egyptian mediators, a pause of up to two months in exchange for the release of all hostages.

"Certainly one of the things he's in the region talking about is the potential for another hostage deal, which would require a humanitarian pause of some length," National Security Council spokesman John Kirby told a briefing at the White House.

"The conversations are very sober and serious about trying to get another hostage deal."

A week-long truce in November saw 105 hostages released, the Israelis among them in exchange for Palestinian prisoners held in Israeli jails.

Israel says around 132 remain in Gaza. That number includes the bodies of at least 28 dead hostages, according to an AFP tally based on Israeli figures.

Kirby said the White House would back a new pause, but declined to specify a timeframe or to confirm the Axios report on a two-month halt.

"If that would give us the opportunity to get hostages out and get more aid in, we would absolutely support a humanitarian pause of a longer length than the week that we were able to accomplish," Kirby added.

A new break in fighting could in theory contribute to a longer-term peace between Israel and Hamas, the White House spokesman added, while cautioning that discussions were at an early stage.

"It's possible that could have some larger implications for the conflict itself, but it's just too soon to know right now," said Kirby.

Israeli Prime Minister Benjamin Netanyahu has faced mounting pressure after Israel lost 24 troops on Monday in its worst day of troop losses so far in Gaza, and over the failure to bring the remaining hostages back.

Netanyahu's vow to destroy Hamas is increasingly seen within Israel's cabinet as incompatible with returning hostages.

Kirby however said that "only the Israelis could answer" whether the troop losses in particular would be a factor in their negotiations.

"It was a terrible day for the IDF (Israeli Defence Forces) yesterday, that's an enormous amount of troops to lose in one day," he said.

Biden has stood firmly behind Israel since the October 7 attacks, but there have been growing tensions with Netanyahu over civilian casualties and over Israel's plans for when the conflict ends.