East Africa's hunger crisis has been described by a US official as one of the worst humanitarian crisis in decades amid stepped-up efforts by Western countries to provide relief aid and a decision by Kenya to open a fourth camp for starving refugees.
Tens of thousands of Somali refugees are flooding camps in Ethiopia and Kenya - at a rate of more than 3,000 new arrivals per day - in search of food after several seasons without rain killed livestock and destroyed crops in Somalia.
"There are many seasoned relief professionals who would tell you we haven't seen a crisis this bad in a generation," Reuben Brigety, the deputy assistant secretary responsible for state department assistance to refugees and conflict victims in Africa, said on Saturday.
"We anticipate that this crisis will get worse before it gets better."
The US was studying how much more it would give in addition to $5m promised on Friday to help Somali refugees, on top of a previously budgeted $63m, Reuben said.
For its part, Germany said it is donating an additional 5m euros ($7m) in humanitarian aid.
Dirk Niebel, the German development minister, said in Berlin on Saturday that "the famine and the humanitarian crisis in the Horn of Africa are a cause of great worry".
He said the emergency aid is in addition to the 3.6m euros ($5m) pledged earlier this year.
Duncan Harvey, the acting country director for Save the Children in Ethiopia, said: "In terms of the sheer numbers of people affected, this is one of the worst droughts the world has seen in a long time."
Robert McCarthy, a UNICEF emergency adviser in Nairobi, discusses the humanitarian crisis
The United Nations Children's Fund (UNICEF) said on Friday it had sent by air emergency nutrition supplies and water equipment into Somalia.
UNICEF said in an update to the media that the supplies were delivered to Baidoa, a town in the Bay region of south-central Somalia, as part of the agency's life-saving assistance for drought-affected children.
At the same time, a senior UN official also warned on Saturday that the plight of millions of people left hungry was set to worsen, with the next rains expected in October and harvests months away.
"We are possibly seeing a perfect storm in the coming months ... We are going to do everything we can to ameliorate it," Anthony Lake, the UNICEF director, told the AFP news agency on his way to the drought-hit northern Kenya region of Turkana.
"We are scaling up in every way we can ... It is very bad now. There will be no major harvests until some time next year. The next six months are going to be very tough."
Little help in Somalia has reached those in the worst-hit area because an al-Qaeda-linked group, al-Shabab, had banned aid work though it recently said it would lift that ban.
Over the last several days, Brigety, the US administration official, has visited camps in Ethiopia and Kenya, and talked to mothers and children who walked for days with little food or water.
Levels of malnutrition among refugees arriving at the camps are very high.
The overall mortality rate at the camps in Ethiopia is seven people out of 10,000 per day, when a normal crisis rate is two per day, Brigety said.
At Kenya's Dadaab refugee camp, the largest in the world, Brigety spoke to a mother who arrived at the camp with six children, including a 7-year-old who has polio that she carried on her back.
The crisis has swelled Dadaab's numbers to nearly 440,000 people, UNHCR said on Friday.
Against this backdrop, the Kenyan government announced on Friday a fourth camp had been opened in Dadaab in an effort to ease congestion.
Antoine Froidevaux, a field co-ordinator for the Medecins Sans Frontieres humanitarian agency, welcomed the new camp, but said the humanitarian organisation was "still very worried about the situation of the new arrivals that are coming in".
And Tarek Jasarevic, a World Health Organisation spokesman, said at least 462 cases of measles, including 11 deaths, had been confirmed in recent months among Somali refugee children in Dadaab.
The aid group Save the Children said on Friday that it had started feeding malnourished refugee children in pre-registration sites at camps in southern Ethiopia.
Because of the overwhelming numbers, refugees are waiting days or weeks to get into the camps, Save the Children said, making the feeding programmes outside a necessity.