The humanitarian situation in war-torn Somalia has deteriorated rapidly, the UN says. Tens of thousands of Somalis have been trying to flee to neighboring Kenya or Ethiopia.
It will be the first time since 1992 that the region has seen famine, a word rarely and only carefully used by humanitarian agencies, the BBC says. Famine is defined as more than 30 percent of children under five years old being acutely malnourished, and four out of every 10,000 children dying daily.
Reuters reports that the UN is expected to make the announcement of famine conditions in Somalia on Wednesday in Nairobi.
An estimated 10 million people have been affected by the drought in east Africa, including 2.85 million in Somalia, the UN says.
Aid efforts have been hampered by the security situation in Somalia. The UN and United States have said relief agencies need greater assurances of safety from armed groups in Somalia to allow staff to deliver aid to those in need.
Al-Shabab, the Islamist insurgents linked to Al Qaeda, controls large parts of south and central Somalia. The group had imposed a ban on foreign aid agencies in its territories in 2009, but has recently allowed some access.
The World Food Program says it is trying to feed 1.5 million people, but estimates that as many as 1 million people are in areas it cannot currently access.
"Once we have the assurances of security and the ability to have full access to deliver and distribute and monitor, then we will be prepared to go back in," Emilia Casella, a spokeswoman for the WFP, told the Associated Press.