Iraq's food harvest is under threat with recent violence in the country driving more than a million people from their homes and farms, the UN's food agency said Wednesday.

With the conflict hitting in two of the country's breadbasket states, the Food and Agriculture Organisation (FAO) warned that the country is "facing serious food security concerns".

While Iraq's harvest had looked promising, "now, however, prevailing civil insecurity and associated access problems, labour shortages, and disruptions in transport and marketing are expected to significantly impact harvesting and domestic production and supply," the FAO said.

The FAO is calling for $12.7 million (9.3 million euros) in emergency aid before August to provide "urgent support" to farmers, and to mitigate the damage to food, income and employment, the agency said in a statement.

More than a million people have abandoned their homes and farms since January, leaving their jobs and goods just when the main harvest of wheat and barley should start, the FAO said.

In total, some two million Iraqis are currently displaced inside the country, many of them affected by the conflict in neighbouring Syria and earlier unrest in the country, according to the agency.

In the last two weeks, a Sunni militant offensive has seen extremists seize a swathe of territory in northern Iraq, leading to the deaths of more than a thousand people and the displacement of hundreds of thousands more.

"If the conflict continues, basic food commodities and other essential items will be increasingly unavailable to the most vulnerable, despite government subsidies," said Fadel El Zubi, the country representative in Iraq.

Two of the regions most affected by the current conflict, Nineveh and Salah ad Din, on average contribute nearly a third of Iraq's wheat production and about 38 percent of its barley.

The FAO said the northern Kurdish region is also under pressure since it is now hosting "a large share" of people who have fled their homes.