Extreme food shortages in parts of the Gaza Strip have already exceeded famine levels, and mass death is now imminent without an immediate cease-fire and surge of food to areas cut off by fighting, the global hunger monitor said Monday.

The Integrated Food-Security Phase Classification (IPC), whose assessments are relied on by U.N. agencies, said 70% of people in parts of northern Gaza were suffering the most severe level of food shortage, far exceeding the 20% famine threshold.

The IPC said it did not have enough data on death rates, but estimated residents would be dying at famine scale imminently, and children under four may already be.

"The actions needed to prevent famine require an immediate political decision for a ceasefire together with a significant and immediate increase in humanitarian and commercial access to the entire population of Gaza," it said.

Some 1.1 million Gazans, about half the population, are experiencing "catastrophic" shortages of food, the worst category, with about 300,000 in the areas now facing the prospect of famine-scale death rates.

The prospect of a man-made famine in Gaza has brought the strongest criticism of Israel from Western allies since it launched its war against Hamas militants after their deadly attack on Israeli territory on Oct. 7.

"In Gaza we are no longer on the brink of famine, we are in a state of famine, affecting thousands of people," EU foreign policy chief Josep Borrell said at the opening of a conference on humanitarian aid for Gaza in Brussels. "Starvation is used as a weapon of war. Israel is provoking famine."

Israeli Foreign Minister Israel Katz said Borrell should "stop attacking Israel and recognize our right to self-defense against Hamas' crimes."

Israel allowed "extensive humanitarian aid into Gaza by land, air, and sea for anyone willing to help," Katz said on X, and aid was "violently disturbed" by Hamas militants with "collaboration" by the U.N.'s aid agency UNRWA.

U.N. Secretary-General Antonio Guterres called the IPC report an "appalling indictment" and said Israel must allow complete and unfettered access to all parts of Gaza.

"This is an entirely man-made disaster — and the report makes clear that it can be halted," he said.

Israel, which initially allowed aid into Gaza through only two checkpoints on the enclave's southern edge, says it is opening more routes by land, as well as allowing sea shipments and air drops. The first boat carrying aid arrived last week.

Aid agencies say they still cannot get enough supplies through or distribute them safely, especially in the north.