Israel and Hamas will agree to prolong a truce in Gaza that had been due to expire on Tuesday, mediator Qatar said, as hostage and prisoner exchanges were set to continue.

With just hours to go before the so-called "humanitarian pause" was to end, both Hamas and Israel had been under international pressure to avoid a return to battle.

Qatari foreign ministry spokesman Majed Al Ansari said "an agreement has been reached to extend the humanitarian truce for an additional two days in the Gaza Strip."

Hamas confirmed in a statement "that an agreement has been reached with the brothers in Qatar and Egypt for an extension of the temporary humanitarian pause for an additional two days, with the same conditions as the previous truce."

Qatar -- with the support of the United States and Egypt -- has been engaged in intense negotiations to establish and prolong the truce in Gaza.

Hamas, which runs Gaza and triggered the latest round of fighting by launching a bloody cross-border raid last month, said it was drawing up a new list of hostages for release.

Meanwhile, the office of Israeli Prime Minister Benjamin Netanyahu said it had informed families of the identities of hostages to be released on Monday, the last day of the initial four-day truce.

Israel has been clear that the pause is designed to allow Hamas to free more of the hostages it is holding since the October 7 attack, which killed 1,200 Israelis including many women and children, according to Israeli officials.

But both sides are under pressure to build on the break in hostilities to allow humanitarian aid to reach civilians in Gaza, where Israel's campaign against Hamas has left almost 15,000 dead, mostly Palestinian civilians, according to Gaza's Hamas government.

The Qatari announcement came after US President Joe Biden, top EU envoy Josep Borrell and NATO Secretary General Jens Stoltenberg all joined a global chorus urging the parties to extend their temporary break in fighting.

As part of the truce deal, Hamas has so far released 39 Israeli hostages, including a four-year-old girl orphaned by the group's October 7 attack, with more expected later Monday.

- 'Long lasting' pause -

Israel has freed 117 Palestinian prisoners under the terms of the agreement. 

In parallel, 19 foreign nationals have also been released by Palestinian militants.

Tearful reunions of families and hostages have brought relief from images of civilian death and suffering in the seven-week war.

"That's our goal, to keep this pause going beyond tomorrow so that we can continue to see more hostages come out and surge more humanitarian relief in to those in need," Biden said Sunday.

The White House welcomed the agreement to extend the truce.

"We would of course hope to see the pause extended further, and that will depend upon Hamas continuing to release hostages," National Security Council spokesman John Kirby told reporters.

Borrell called for the pause to be prolonged "to make it sustainable and long lasting while working for a political solution." 

"Nothing can justify the indiscriminate brutality Hamas unleashed against civilians," he said. "But one horror cannot justify another horror."

Three successive days of hostage releases have buoyed spirits in Israel, with tearful reunions weeks after Hamas militants poured across the border on October 7.

The third group of hostages released Sunday included a four-year-old American citizen called Abigail whose parents were both killed in the Hamas attacks.

Inside Gaza, the Hamas-run health ministry complained that, despite the four-day pause, no fuel had been taken to generators in hospitals in the north of the Gaza Strip.  

And Yahya al-Siraj, the mayor of Gaza City, complained that without fuel the territory could not pump clean water nor clear waste accumulating in the streets, warning of a potential public health "catastrophe". 

- Fight 'until victory' -

Israel has faced mounting pressure to extend the pause mediated by Qatar, the United States and Egypt, though its leaders have dismissed any suggestions of a lasting halt to the offensive.

"We continue until the end -- until victory," Netanyahu said in Gaza on Sunday, on the first visit by an Israeli premier since 2005.

His office has proposed a war budget of 30 billion shekels ($8 billion) for 90 days.

Wearing military fatigues and surrounded by soldiers, Netanyahu vowed to free all the hostages and "eliminate Hamas", in footage posted online by his office.

In another sign of mounting international concern, UN rights experts called Monday for independent investigations into alleged war crimes and crimes against humanity carried out in Israel and the Palestinian territories since October 7.

Morris Tidball-Binz, the United Nations special rapporteur on extrajudicial executions, and Alice Jill Edwards, the special rapporteur on torture, issued a joint statement stressing the need for "prompt, transparent and independent investigations".

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