Efforts to hammer out a temporary truce in Gaza intensified on Tuesday after months of war that have devastated the Palestinian territory and pushed hundreds of thousands to the brink of famine.

While a UN-backed assessment said 300,000 people in Gaza's north would face famine by May without a surge of aid, US Secretary of State Antony Blinken said everyone in Gaza was now in need of humanitarian aid.

UN human rights chief Volker Turk blamed Israel for the hunger crisis, telling reporters in Geneva they were blocking aid and conducting the conflict in a way that "may amount to the use of starvation as a method of war."

Israeli troops on Tuesday pressed an assault on Gaza's biggest hospital, which they allege is being used for military purposes.

The military said more than 50 fighters had been killed. Hamas said the assault on Gaza City's Al-Shifa Hospital was a war crime.

Israel's spy chief David Barnea was in Qatar on Monday for a new round of talks with Egyptian and Qatari mediators, after they failed to secure a truce for the Muslim holy month of Ramadan, which began last week.

Qatar's foreign ministry spokesperson Majed al-Ansari said he was "cautiously optimistic" about the latest negotiations but it was "too early to announce any successes."

The new push for a truce follows a Hamas proposal for a six-week ceasefire, an increase in aid and the initial release of about 42 hostages in exchange for Palestinian prisoners held by Israel.

During the proposed truce, Israeli forces would withdraw from "all cities and populated areas" in Gaza, according to a Hamas official.

Ansari said they were expecting a counter-proposal to be presented to Hamas and technical talks would continue.

The bloodiest ever Gaza war broke out after Hamas's unprecedented October 7 attack resulted in about 1,160 deaths in Israel, mostly civilians, according to a tally of Israeli official figures.

Militants also seized about 250 hostages, of whom Israel believes 130 remain in Gaza, including 33 who are presumed dead.

Israel has responded with a relentless offensive against Hamas that Gaza's health ministry says has killed at least 31,726 people, most of them women and children. (AFP)