The report was written by an expert team using the globally recognized IPC methodology. The IPC, or Integrated Food Security Phase Classification, is a system of analyzing food security on a five-point scale, where five is "famine," Reuters reported.
Saudi Arabia has been incessantly pounding Yemen since March 2015 in a bid to reinstall the country’s ex-government and crush the Houthi Ansarullah movement.
A naval embargo imposed by the Saudis, fighting around the ex-government-controlled port of Aden and airstrikes on the port of Yemen's Hudaydah have severely reduced imports since 2015.
A lack of fuel, coupled with insecurity and damage to markets and roads, has also prevented supplies from being distributed.
The Office for the Coordination of Humanitarian Affairs (OCHA) in February said some 18.8 million people, or more than two-thirds of Yemen's population, need assistance. Some 10 million of those are "acutely affected" and need assistance for food, water, health care and protection.
The UN agency is seeking $2.1 billion this year to help people in Yemen.
OCHA last month estimated that some 10,000 civilians have died in the conflict. However, according to the latest tally by a Yemeni monitoring group, the military aggression has claimed the lives of over 11,400 Yemenis, including women and children.