World cereal output is expected to hit record highs this year but food insecurity is worsening across the globe thanks to Ebola and civil conflicts, the UN's food agency said Thursday.

The Food and Agriculture Organization said 2014 was heading to be a bumper year for cereals, with "an all-time of more than 2.5 billion tonnes".

That was due to a record maize output in the United States and bumper crops in Europe, a FAO report said.

The record harvest "will outpace projected world cereal utilisation in 2014/15 allowing stocks to rise to their highest level since 2000".

But the report warned that food insecurity was worsening in a number of countries due to conflicts, adverse weather and the outbreak of Ebola in western Africa, which began to spread just as crops were being planted in Guinea, Liberia and Sierra Leone.

Poor weather in the Sahel meanwhile was expected to reduce the harvest by as much as 38 percent in neighbouring Senegal.

But nowhere was the situation worse than in Syria, where conflict has combined with a weak harvest to leave 6.8 million people facing insecurity.

In Iraq, where the number of people displace has tripled to 2.8 million since 2013, the situation is also "acutely serious," FAO said.

In all, 38 countries are at risk of , 29 of them in Africa.