Rome (AFP) – The United Nations on Friday officially declared a famine in Gaza, the first time it has done so in the Middle East, with experts warning 500,000 people face "catastrophic" hunger.

Top UN officials put the blame squarely on Israel, accusing it of "systematic obstruction" of aid deliveries to the war-ravaged Palestinian territory -- sparking a sharp response.

The assessment of famine was made by the Integrated Food Security Phase Classification Initiative (IPC), a coalition of monitors tasked by the UN to warn of impending crises.

It defines famine as occurring when 20 percent of households have an extreme lack of food; 30 percent of children under five are acutely malnourished; and at least two in every 10,000 people die daily from outright starvation or from malnutrition and disease.

UN agencies have for months been warning of the deteriorating humanitarian situation in Gaza, which has worsened as Israel steps up its offensive against Hamas.

The Rome-based IPC said that "as of 15 August 2025, famine (IPC Phase 5) -- with reasonable evidence -- is confirmed in Gaza governorate", the area that encompasses Gaza City and its surroundings".

The UN estimates that nearly one million people currently live in the Gaza governorate.

"After 22 months of relentless conflict, over half a million people in the Gaza Strip are facing catastrophic conditions characterised by starvation, destitution and death," the IPC report said.

The IPC projected that famine would spread to the Deir el-Balah and Khan Yunis governorates by the end of September, encompassing more than three-quarters of the total Gaza population, or nearly 641,000 people.

The IPC reported the most severe deterioration in the situation since it began analysing hunger in the Gaza Strip, which it called "entirely man-made".

It said the change was driven by a sharp escalation in the conflict and the resulting massive displacement of people, combined with the severe restriction of access to humanitarian and commercial supplies of food.

UN rights chief Volker Turk said "it is a war crime to use starvation as a method of warfare".

Tom Fletcher, the UN's emergency relief coordinator, told reporters in Geneva that "food stacks up at borders because of systematic obstruction by Israel".

He said the famine in Gaza should "haunt us all".

UN Secretary-General Antonio Guterres renewed calls for an immediate ceasefire in the war, the release of all hostages taken by Hamas from Israel, and full humanitarian access to Gaza.

"We cannot allow this situation to continue with impunity," he said.

Children are particularly hard hit by the lack of food.

In July alone, more than 12,000 children were identified as acutely malnourished -- a six-fold increase since January, according to UN agencies.

"The signs were unmistakable: children with wasted bodies, too weak to cry or eat, babies dying from hunger and preventable disease," said UNICEF Executive Director Catherine Russell.

The local food system has collapsed, with an estimated 98 percent of cropland in the Gaza Strip either damaged, inaccessible or both, the IPC said. Livestock is decimated and fishing is banned.

The severe deterioration of the health system and the lack of safe drinking water and adequate hygiene compound the crisis.

Gathering information is extremely difficult in Gaza.

The IPC said conditions in the North Gaza Governorate, north of Gaza City, may well be worse, but said it did not have enough data.