Tens of thousands of Somalis are feared dead in the world's worst famine in a generation, the United Nations said.
It came as the United States yesterday eased restrictions on funding food appeals for the famine-hit African state -- saying it would allow emergency funds to be spent in areas controlled by al Qai'da-linked militants if the fighters did not interfere with aid distribution.
"Somalia is facing its worst food security crisis in the last 20 years," Mark Bowden, the UN's top official in charge of humanitarian aid in the country, said.
"This desperate situation requires urgent action to save lives," he added.
The crisis is the worst since 1991-92, when hundreds of thousands of Somalis starved to death, Mr Bowden said.
That famine prompted intervention by an international peacekeeping force, but it eventually pulled out after two American Black Hawk helicopters were shot down in 1993.
Since then, Western nations have mainly sought to contain the threat of Islamic terrorism from Somalia.
Aid agency Oxfam said $1bn (€700m) was needed for famine relief. Yesterday, the US announced an additional €20m in emergency funding on top of €304m already given this year.
Most importantly, as long as the Islamists do not interfere with aid distributions, those new US funds are not restricted under rules implemented in 2009 that are designed to keep food and money from being stolen by the uprising.
Al-Shabaab, Somalia's Islamist rebels, promised an amnesty last week which prompted calls from aid workers for a lifting of the ban on US aid to southern Somalia.
"We are determined to test that pledge," said Dr Raj Shah, head of the US Agency for International Development (USAID).
"If (the rebels) are willing to allow access we are willing to stand fully with the humanitarian actors," he added.
Somalia is the most dangerous country in the world to work in, according to the UN's World Food Programme (WFP), which has lost 14 relief workers in the past few years.
Kidnappings, killings and attacks on aid convoys occur frequently.
Two years ago, the WFP pulled out of Islamist-controlled southern Somalia after the rebels demanded cash.
US military operations against terror suspects have also disrupted humanitarian operations, said Mr Bowden.
Insurgents vowed to target foreign aid workers after a US missile strike killed the head of the Islamist al-Shabab militia and 24 other people in 2008.
The Horn of Africa is suffering a devastating drought compounded by war, neglect, poor land policies and spiralling prices. Some areas in the region have not had such a low rainfall in 60 years, Oxfam said.
Yet only parts of Somalia are technically suffering from famine, defined as when two adults or four children per 10,000 people die of hunger each day and a third of children are acutely malnourished.
In some areas, six people are dying a day and more than half of children are acutely malnourished, Mr Bowden said.
Prices of staple foods have increased 270pc over the last year, compounding the misery.
Somalia's civil war is partly to blame, said Joakim Gundel, who heads Katuni Consult, a Nairobi-based company often asked to evaluate international aid efforts in Somalia.
He said the emergency was partly caused by a complex, 20-year civil war.
"People are suffering and there is a need to respond," he said. "But drought is not the only cause. Conflict is a key reason and it is not being addressed properly."