South Sudan descended into civil war in 2013, just two years after gaining independence.

The united nations'peacekeeping mission involves 12 thousand troops from dozens of countries.

British Prime Minister David Cameron announced Monday that up to 300 soldiers would join the the mission,while further 70 British troops will be deployed to work with a U.N. force supporting the African Union's peacekeeping mission in Somalia.

“It is not just living up to our international obligations but we would benefit if Somalia has a future free from extremism. We would benefit if South Sudan as a country can function and not drive huge numbers of migrants across the Mediterranean.”

The British troops will not play any role in the fighting, but will instead provide combat training and logistical support.

The deployment is unlikely to achieve Cameron's desired outcome, said Mareike Schomerus, a South Sudan specialist at the Overseas Development Institute in London.

“This clear cause and effect-the UK sends 70 troops to Somalia, 300 to South Sudan, there will be less terrorism and less migration - just does not exist.”

There are other interests and other reasons why it's a good idea to contribute to a U.N. peacekeeping mission, but it's not to address migration or terrorism in the UK.”

Rival government and opposition forces signed a peace deal last month-but sporadic fighting continues.

In the worst hit areas, the hospitals are full of malnourished children.

40 percent of the population is reliant on food aid.

The U.N. said that unless treatment is scaled up immediately, 50,000 children are likely to die.

Melany Markham of the charity World Vision said it's vital the peace deal holds.

"We are now delivering food aid and nutrition programs, other items that people are in desperate need of. So we are actually very positive and this has only happened since the signing of the peace agreement.”

Aid agencies warn that the world must act fast to avert a desperate shortage of food-or the toll from the South Sudan conflict could rise sharply.