"The risk of famine in Gaza is increasing with each passing day," the UN agency said on X, citing a recent report of the Integrated Food Security Phase Classification (IPC).
"The world cannot stand by and watch people starve," it added.
According to the report published on Thursday, more than 576,600 people in the besieged Palestinian enclave of Gaza are facing "catastrophic hunger (IPC Phase 5) and starvation."
"The entire population of Gaza – roughly 2.2 million people – are in crisis or worse levels of acute food insecurity," it said.
The IPC is a multi-stakeholder platform that analyzes data to determine the severity and magnitude of hunger crises in line with internationally recognized scientific standards.
The Israeli onslaught has left Gaza in ruins, with half of the coastal territory's housing stock damaged or destroyed, and nearly 2 million people displaced within the densely populated enclave amid shortages of food, clean water, and hygienic and medical supplies.
The Palestinian death toll from Israeli attacks on the Gaza Strip has soared to 20,057 since Oct. 7, with at least 53,320 others injured, the Health Ministry in the blockaded enclave said on Friday.