Famine is now occurring in Gaza City, according to the world’s leading authority on food crises. The Integrated Food Security Phase Classification released an analysis Friday, saying more than half a million people in Gaza are trapped in famine, suffering widespread starvation and preventable deaths.

An announcement of famine — as has now happened regarding Gaza — is a complicated decision. Here's what must be considered before such a declaration is made.

Israel has called the United Nations' declaration of famine in parts of Gaza an "outright lie," but multiple U.N. bodies, more than 100 humanitarian groups, and several of Israel's own allies have warned for months that the war and Israel's restrictions of food into Gaza are causing starvation among civilians.