Somalia's president has declared a famine in his drought-stricken country and called for more international help to deal with the crisis.

While touring a displaced-persons camp in the capital, Mogadishu, on Tuesday, President Sheikh Sharif Sheikh Ahmed said food has become so scarce that there is “in fact a famine” in his country.

The president blamed the food crisis for an exodus of starving Somalis into neighboring Ethiopia and Kenya. Aid groups say many Somalis are dying while trying to walk to refugee camps or shortly after arriving in the camps.

Separately, the United Nations is expected to declare a famine in at least parts of Somalia on Wednesday.

The Horn of Africa is experiencing its worst drought in six decades. U.N. officials have said more than 11 million people are in need of emergency food aid.

On Tuesday, the U.N. refugee agency, UNHCR, said it needs more security assurances from Somali insurgents in order to provide the massive level of aid needed in the country.

Militant group al-Shabab has said it welcomes the return of relief organizations, after barring them from its strongholds in central and south Somalia more than a year ago.

But UNHCR spokesman Adrian Edwards told VOA that the agency must still keep a “low profile” and work through partners to avoid being targeted by al-Shabab and other armed groups.

The United States said Tuesday it is assessing whether al-Shabab is following through on its promise to let aid groups operate freely in Somalia.

The top U.S. diplomat to Africa, Johnnie Carson, said al-Shabab's policies have been “wreaking havoc” on Somalis.

The country has been wracked with lawlessness and deadly violence for years. Al-Shabab is fighting to overthrow the U.N.-backed Somali government and set up a strict Islamic state.