The United Nations warned Monday that Gaza was facing its most severe humanitarian crisis since the war began, with no aid entering the territory for weeks and conditions rapidly deteriorating following a ceasefire's collapse.

The UN's alarm came as Palestinian President Mahmud Abbas and French President Emmanuel Macron called for an "urgent" ceasefire in Gaza.

Israel resumed an intense military offensive on Gaza after a ceasefire that came into effect on January 19 collapsed two months later over differences regarding the next phase of the truce.

Hundreds of thousands of people have since been displaced, with Israel blocking the entry of humanitarian aid from March 2, even before the truce disintegrated on March 18.

Medical supplies, fuel, water and other essentials are in short supply, the UN says.

"The humanitarian situation is now likely the worst it has been in the 18 months since the outbreak of hostilities," said the UN Office for the Coordination of Humanitarian Affairs.

In a statement, OCHA said no supplies had reached Gaza for a month and a half.

"Due to........

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