GENEVA - The United Nations on Wednesday asked donor nations to give $7.7 billion to pay for humanitarian emergencies from Afghanistan to Zimbabwe next year, significantly less than the global body has requested for 2011.

Somalia, Sudan and Kenya -- where tens of thousands of Somalis have sought shelter from war and famine -- top the UN's projections for the costliest emergencies.

In all, the appeal is expected to meet the needs of 51 million people in 16 countries, the UN's aid chief Valerie Amos told reporters in Geneva.

The 2011 appeal is significantly lower than the $8.9 billion that the global body requested for the current year. But requests to UN donors are revised throughout the year to respond to unforeseen disasters, which this year included floods in Pakistan, the civil war in Libya, and the ongoing conflict in Yemen.

Amos said the biggest amount in next year's appeal -- about $1.5 billion -- will be devoted to Somalia. This is followed by $1.1 billion for Sudan and $764 million for Kenya.

Some 4 million people in the Horn of Africa need humanitarian aid due to the ongoing drought and insecurity in the region, Amos said. Although the UN has downgraded some regions from "famine" to "emergency," gains could be short-lived, she said.

"The situation remains fragile, and aid organizations will only be able to sustain these improvements if the current level of assistance is maintained," said Amos.

Newly independent South Sudan has humanitarian needs expected to cost $763 million next year, followed by Congo, Chad, Yemen, Afghanistan, the Palestinian territories and Zimbabwe.