"Yemen's fragile food security is deteriorating fast," UN spokesman Stephane Dujarric said at a daily news briefing on Monday, Xinhua News Agency reported.
"Ten out of Yemen's 22 governorates are classified as facing food insecurity at emergency level -- one step below famine."
Yemen has been facing a mounting humanitarian crisis since conflict broke out in the already impoverished Arab country in March.
The Middle East country's extremely fragile humanitarian situation may be further worsened Tuesday when a category 3 cyclone is expected to hit Yemen's mainland, the UN Office for the Coordination of Humanitarian Affairs (OCHA) has warned.
Pointing to a category 3 cyclone which is bearing down on Yemen's southern coast on Tuesday, Dujarric said, "The effects of the cyclone may be felt over large parts of Yemen but are likely to be more severe in the coastal governorates Shabwah and Hadhramaut."
These governorates have a combined population of about 1.8 million people, 1.4 million of whom are already considered in need of humanitarian support, according to Dujarric.