The worst-case scenario of famine is "currently playing out" in the Gaza Strip, UN-backed global food security experts warn.

A new assessment by the Integrated Food Security Phase Classification (IPC) says there is mounting evidence that widespread starvation, malnutrition and disease are driving a rise in hunger-related deaths among the 2.1 million population.

"Latest data indicates that famine thresholds have been reached for food consumption in most of the Gaza Strip and for acute malnutrition in Gaza City," it adds.

The IPC says immediate action must be taken to end the hostilities and allow for an unimpeded, large-scale, life-saving humanitarian response.

The report does not formally classify Gaza as being in a famine, saying that can only be made through analysis that will be conducted "without delay".