Somali's newly elected President Mohamed Abdullahi Mohamed on Tuesday declared a "national disaster" due to severe drought which aid agencies say has left some three million in crisis.

The Horn of Africa nation is one of three countries -- along with Yemen and Nigeria -- on the verge of famine which has already been declared in South Sudan -- an unprecedented food crisis.

"The president has appealed to the International Community to urgently respond to the calamity in order to help families and individuals to recover from the effects of the drought disaster to avoid humanitarian tragedy," read a statement from the presidency.

The World Health Organisation (WHO) warned Monday that Somalia was at risk of its third famine in 25 years. The last one in 2011 killed some 260,000 people.

The agency said more than 6.2 million people -- half of the population -- needed urgent humanitarian aid, including almost three million who are going hungry.

Meanwhile, the drought has led to a spread of acute watery diarrhoea, cholera and measles and nearly 5.5 million people were at risk of contracting waterborne diseases.

According to the WHO more than 363,000 acutely malnourished children and 70,000 severely malnourished children needed urgent, life-saving support.

In South Sudan 100,000 people are in famine conditions.

This means 20 percent of the population in the affected area has extremely limited access to basic food, acute malnutrition is higher than 30 percent, and more than two per 10,000 people are dying every day.

Overall, more than 20 million people face starvation in the four countries. 

Of the four famine alerts, only one -- Somalia -- is caused by drought, while the other three stem from conflicts, described as "man-made food crises."

Source: AFP