Famine is "imminent" in northern Gaza, where no humanitarian group has been able to provide aid since January 23, the World Food Programme warned Tuesday, as Israel wages war on Palestinian militant group Hamas.

With a dire humanitarian emergency unfolding in the Gaza Strip and the main UN aid agency there struggling to cope, other bodies have called for help in reaching the thousands of Palestinians in desperate need.

"If nothing changes, a famine is imminent in northern Gaza," WFP's deputy executive director Carl Skau told the UN Security Council, while his colleague from the UN humanitarian office OCHA, Ramesh Rajasingham, warned of "almost inevitable" widespread starvation.

As aid remains blocked from entering northern Gaza by Israeli forces, and only enters the rest of the territory in dribs and drabs, UN aid chief Martin Griffiths last week wrote to the Security Council calling on members to act to prohibit "the use of starvation of civilian population as a method of warfare."

"Here we are, at the end of February, with at least 576,000 people in Gaza -- one-quarter of the population -- one step away from famine, with one in six children under two years of age in northern Gaza suffering from acute malnutrition and wasting," OCHA's Rajasingham said.

Some 97 percent of groundwater in Gaza is "reportedly unfit for human consumption" and agricultural production is beginning to collapse, warned Maurizio Martina, deputy director general of the UN's Food and Agriculture Organization (FAO).

Aid is ready and waiting at the border, a spokesman for UN Secretary-General Antonio Guterres also said Tuesday.

"WFP colleagues also tell us that they have food supplies at the border with Gaza, and with certain conditions they would be able to scale up feeding up to 2.2 million people" across the Strip, Stephane Dujarric told reporters.

"Almost 1,000 trucks carrying 15,000 metric tons of food are in Egypt ready to move," he said.

- Aid blocked by Israel -

But Israeli forces are "systematically" blocking access to Gaza, said Jens Laerke, spokesman for OCHA, in Geneva earlier Tuesday.

All planned aid convoys into the north have been denied by Israeli authorities in recent weeks.

The last allowed in was on January 23, according to the World Health Organization.

But Israeli deputy ambassador to the UN Jonathan Miller countered that "it is not Israel who is holding up these trucks," instead placing the blame on the UN, which he said must distribute aid "more effectively."

"There is no limit to the amount of humanitarian aid that can be sent to the civilian population of Gaza," he said, adding that since the beginning of 2024 Israel had only denied 16 percent of requests to deliver aid, and those were due to risks the shipments could end up in Hamas' hands.

The main UN aid agency in Gaza, UNRWA, meanwhile, is "at breaking point," its head said last week. As donors freeze funding, Israel exerts pressure to dismantle the body and humanitarian needs soar.

"Israel must do more," US deputy ambassador to the UN Robert Wood said Tuesday, calling on the country to "facilitate the opening of additional crossings" for aid.

"We should all have been convinced by now that our action is needed, indeed was needed a long time ago," said Slovenian ambassador Samuel Zbogar.

The Hamas attack on October 7 that triggered the war resulted in the deaths of around 1,160 people in Israel, mostly civilians, according to an AFP tally based on official figures.

Militants also took about 250 hostages, 130 of whom remain in Gaza, including 31 presumed dead, according to Israel.

Israel's military campaign has killed at least 29,878 people in Gaza, mostly women and children, according to the territory's health ministry.

US, Qatar hope for truce within days

Mediator Qatar expressed hopes Tuesday that a new truce between Israel and Hamas could be secured within days, after US President Joe Biden said a ceasefire could start next week and last through Ramadan.

As a dire humanitarian crisis unfolds in Gaza, the UN humanitarian agency OCHA and the United States appealed for aid to be allowed into the war-battered Palestinian territory.

Egyptian, Qatari and US mediators have been in a protracted bid to broker a ceasefire nearly five months into the devastating war.

Negotiators are seeking a six-week pause and the release of Israeli hostages held in Gaza since Hamas's October 7 attack.

Several hundred Palestinian detainees held by Israel may also be released under the deal, media reports suggest.

"My hope is by next Monday we'll have a ceasefire" but "we're not done yet", Biden said.

State Department spokesman Matthew Miller said it was possible a deal could be reached by the weekend.

"We're closer today than we were yesterday," he said, adding details were still being ironed out.

Qatar's emir, Sheikh Tamim bin Hamad Al-Thani -- whose country hosts Hamas's political leadership and helped broker a one-week truce in November -- met in Paris with French President Emmanuel Macron.

Qatari foreign ministry spokesman Majed al-Ansari said Doha was "hopeful, not necessarily optimistic, that we can announce something" before Thursday.

"We are going to push for a pause before the beginning of Ramadan", the Muslim fasting month which starts on March 10 or 11, depending on the lunar calendar, Ansari said.

"But the situation is still fluid on the ground."

- 'Nothing but dust' -

There has been huge international pressure for Israel to hold off on sending troops into Rafah, where nearly 1.5 million Palestinian civilians have sought refuge.

Israeli Prime Minister Benjamin Netanyahu has stressed that any truce would delay, not prevent, a ground invasion of Rafah in Gaza's far south, which he said was necessary to achieve "total victory" over Hamas.

Israel's military campaign has killed at least 29,878 people in Gaza, mostly women and children, according to the territory's health ministry.

The Hamas attack that triggered the war resulted in the deaths of around 1,160 people in Israel, mostly civilians, according to an AFP tally based on official figures.

Militants also took about 250 hostages, 130 of whom remain in Gaza, including 31 presumed dead, according to Israel.

Egyptian Foreign Minister Sameh Shoukry warned any assault on Rafah "would have catastrophic repercussions" across the region.

Ahead of the threatened ground incursion, the area has been hit repeatedly by Israeli air strikes.

Abu Khaled Zatmeh, whose nephews were killed in bombardment in Rafah, said the family had been "getting ready to eat when the strike occurred, and three floors collapsed suddenly".

"People began pulling out the martyrs, all of whom were my nephews," he told AFP.

He said there were "no more" basic supplies in the besieged territory, adding that "even if they allow people to return to the north, there are no houses left -- nothing but dust".

Gaza's health ministry spokesman Ashraf al-Qudra said two babies had died of "dehydration and malnutrition" at Kamal Adwan hospital in the north.

- 'War must continue' -

Netanyahu has faced increasing public pressure over the fate of the remaining hostages.

Itamar Ben Gvir, Israel's far-right national security minister, said Netanyahu should not accept Hamas's "delusional requests" in negotiations, adding that "the war must continue", according to news website Ynet.

A small crowd gathered in Tel Aviv for an anti-war rally urging a ceasefire.

"I feel that there's nothing that justifies this vast killing of innocent people," said protester Michal Sapir, 58.

A Hamas source, speaking on condition of anonymity, said the proposed 42-day truce could potentially be "renewed" and would see one Israeli hostage released every day, each in return for 10 Palestinian prisoners.

Instead of a complete withdrawal of Israeli forces from Gaza -- a demand rejected by Netanyahu -- the source said the military may leave "cities and populated areas", allowing the return of some displaced Palestinians.

In northern Gaza, desperate Palestinians searched for food, with many people eating animal fodder and even leaves.

"I have not eaten for two days," said Mahmud Khodr, a resident of Jabalia refugee camp in the north, where children roamed with empty pots. "There is nothing to eat or drink."