The United Nations is poised to declare a famine in parts of Somalia as a humanitarian emergency persists in drought-affected communities across the Horn of Africa.

More than 10.7 million people are in need of assistance as the Horn of Africa experiences its driest period in 60 years, says the United Nations Office for the Co-ordination of Humanitarian Affairs.

Several humanitarian groups have estimated the number at risk is already over 11 million, as people struggle to cope with persistent drought, high food prices and conflict.

The UN has not yet declared the current food crisis a famine, but Brian Stewart, a distinguished senior fellow at the Munk School for Global Affairs at the University of Toronto, told CBC News that the UN is expected to declare a famine in some areas of Somalia within 48 hours.

In parts of the Horn of Africa, food insecurity has already reached emergency levels — one level below famine. "Famine/catastrophe" is the worst-case scenario on a five-level scale used to gauge food security.

The scale uses several indicators to declare a famine, including acute malnutrition in more than 30 per cent of children, at least two deaths per 10,000 people every day and access to less than four litres of water a day. Large-scale displacement of people, civil strife and pandemic illness are also taken into consideration.

The last time a major famine was declared in the Horn of Africa was 1984-85, when a catastrophic drought in Ethiopia left more than one million people dead.

South Somalia has been particularly hard hit by the current crisis, with thousands of people fleeing the country every day.

"Added to the drought, this is a region which suffers insecurity and conflict, population growth, poverty and over-utilization of land," said Valeria Amos, the UN emergency relief co-ordinator for humanitarian affairs.

What is a famine? The United Nations has not yet declared the food crisis in the Horn of Africa a famine, but parts of the region have been classified as being in a "humanitarian emergency" phase, which is one step away from a "famine" designation on the UN's scale of food security assessment.

Roughly 120,000 people are sheltering in Dollo Ado, Ethiopia. In Kenya, more than 380,000 people are camped at Dadaab, a sprawling network of camps that is well over capacity and ill-equipped to serve the influx of people who are still pouring into the area from neighbouring Somalia.

Aid groups and UN agencies are calling for more assistance to meet the mounting need. Roughly $835 million US has been received to assist people in the Horn of Africa, but $1 billion more is needed, the UN said.

Canada has contributed roughly $22 million for humanitarian assistance to the region this year, but is expected to announce new funding within a week, Stewart said.

"Normally Canada is expected to pay up to four per cent of major humanitarian emergencies," he added.

Stewart, who was one of the first journalists to alert the world to the Ethiopian famine in the 1980s, said the key need is to buy sufficient food and water from inside Africa.

"Shipments from abroad take far too long and take away from Africa's own potential to deliver good and fast supplies," he noted.

Canadian International Co-operation Minister Bev Oda will travel to the Dadaab refugee camps as part of a visit to drought-stricken areas. She's expected to meet with government representatives and aid groups who have been working with people affected by the growing food crisis.