Two years of failed harvests amid al-Shabab extremist attacks prompted Somalia's President Mohamed on Tuesday to declare a "national disaster" at a UN-sponsored Mogadishu conference to discuss how to deal with the drought.

"We cannot and must not wait," Mohamed told the meeting, and urged the international community to "avoid humanitarian tragedy."

He also appealed to the Somali business community and diaspora world-wide to help out.

Desperate stream into Mogadishu

In recent weeks, thousands of desperate people - often mothers carrying malnourished infants have streamed into Somalia's capital seeking food. The situation is overwhelming already-stretched aid agencies.

A lack of clean water in many areas has posed the additional threat of cholera and other diseases, UN experts have warned.

On Monday, the African Union-backed Somali government said its ongoing conflict against Islamist al-Shabab rebels had compounded large-scale harvest failures and livestock deaths.

The situation had made Somalis "vulnerable to exploitation, human rights abuses and to criminal and terrorist networks," according to a government statement.

"The ravaging drought forced them to flee from their homes," said Abdullah Mohamed Ibrahim, deputy director of Sorrdo, a Somali organization. "They are so desperate."

Famine warning

Urgent nutrition support was needed for 363,000 acutely malnourished children, "including 71,000 who are severely malnourished," said the US Agency for International Development via its Famine Early Warning Systems Network.

The current UN humanitarian appeal for Somalia in 2017 is $864 million (816 million euros) to assist 3.9 million people. Last month, the UN's World Food Program requested an extra $26 million.

Last week, UN secretary general Antonio Guterres, who previously led the UN's refugee agency, singled out Somalia along with Yemen, Sudan and Nigeria as four regions requiring $4.4 billion.  So far, just $90 million has been collected.

Violent conflict was a common thread in all four countries, Guterres pointed out.

US military reevaluates Somalia

Last weekend, the head of the US military's Africa Command, General Thomas Waldhauser, said the Pentagon was taking a "fresh look at Somalia" to find ways to weaken al-Shabab's decade-long insurgency.

Other officials quoted anonymously by Associated Press said the US was considering sending special operations forces to assist Somalia's national army and ease restrictions on US airstrikes. Currently, it has only advisers present.

The officials also said the African Union was planning to pull out its 20,000 peaceceeping forces from Somalia in 2020.

Al-Shabab has been ousted from most Somali cities and towns, but continues to stage suicide bombings. In an attack on Monday, five Somali soldiers were wounded.