By David Willey BBC correspondent in Rome

Aid agencies fear for ordinary Iraqis

The United Nations food agency, believing that it may be facing the largest and most costly humanitarian crisis in history, is making contingency plans to feed the people of Iraq.

In New York, the UN Secretary General is seeking immediate authorisation from the Security Council to take over the agency's oil-for-food programme.

It has been jointly administered until now by Baghdad and the UN.

The programme, which has been in operation since 1996, collapsed with the outbreak of war and the evacuation of UN personnel, leaving 60% of Iraqis without access to fresh food.

Officials at the World Food Programme (WFP) headquarters in Rome are deeply concerned.

OIL-FOR-FOOD Programme aims to give Iraqis 2,470 calories per day 570,000 tonnes of food a month 44,000 distribution agents Five entry points $1.27bn for current 6 months Aid agencies' race against time

Under their new plan Iraq's oil revenues are channelled into a UN bank account from which Saddam Hussein has been paying for food, medicine and other basic necessities for the civilian population.

The programme avoids the UN trade embargo imposed after Iraq's invasion of Kuwait in 1990.

WFP officials say the Iraqis have only about six weeks' food supplies in reserve.

Their warehouses are almost empty and unless very large quantities of food reach Iraq soon, there could be a devastating hunger crisis.

So far the UN agency has stockpiled about 30,000 tonnes of food in countries bordering Iraq - that is enough to feed two million people for one month.

Open borders plea

But Iraq's population is 26 million and if the war drags on, in a month's time the agency might have to feed the entire population.

Hundreds of thousands of tonnes of food have to be ordered within days.

The final cost could be more than $1bn.

Meanwhile, in Geneva, another UN agency, the High Commission for Refugees, has appealed to Iraq's neighbours to keep their borders open to people fleeing the war.