CAFOD director, Chris Bain, said: "Vulnerable people in East Africa are now on the brink of starvation and urgently need life-saving assistance. We have been working over the long-term with our partners in some of the worst hit areas, but have reached a point where we need more support to help communities facing severe hunger.
"Our common humanity calls on us to take action and respond to the suffering; restoring dignity and hope through the vital aid we need to deliver."
The spotlight was thrown on the growing crisis last month when the UN declared two areas in South Sudan as officially categorised as experiencing famine conditions.
A formal declaration of famine means that people have already begun to starve. UN and food organisations define famine as when more than 30 percent of children aged under five suffer from acute malnutrition and mortality rates are two or more deaths per 10,000 people every day, among other criteria. In South Sudan, there is grave concern that a further one million people are classified as being on the brink of famine in Unity State.
CAFOD and Trocaire are working with our Catholic Church partners to get humanitarian aid to vulnerable families. Fergus Conmee, CAFOD's Head of Africa, is just back from Yirol in central South Sudan.
"When meeting with local health coordinators, village chiefs, men, women and children, the resounding message they all gave was "we are hungry, no one seems to be noticing", he said.
"I met one man who had already gone blind as a result of extreme hunger. Its impact is evident in the thinness of children, the way clothes hang from bodies of people already suffering and the weary looks of people who know that over the next six months, things are only going to get worse for them and their families."
Severe droughts, erratic rains, entrenched civil conflicts and failing economies have exacerbated the suffering, pushing other countries - Somalia, North East Nigeria and Yemen, as well as Kenya and Ethiopia, to the extreme edge of catastrophe with vulnerable lives at risk of malnutrition, illness and death.
In a pastoral letter in February, the Catholic Bishops of South Sudan called on the international community to take action. They said: "Our country is gripped by a humanitarian crisis - famine, insecurity and economic hardship. Our people are struggling simply to survive. While there have been poor rains in many parts of the country, there is no doubt that this famine is man-made, due to insecurity and poor economic management.
"Millions of our people are affected, with large numbers displaced from their homes and many fleeing to neighbouring countries, where they are facing appalling hardships in refugee camps."
The Bishops called on the international community "for immediate and unconditional concrete intervention and action before thousands of innocent lives are carried away and before it is too late."
CAFOD director Chris Bain said: "At the heart of our Catholic communities across England and Wales is an amazing compassion and generosity in response to the suffering of our poorest sisters and brothers. We must now put all our efforts into scaling up our response with our local trusted Church partners, who are already on the frontline doing all that they can, to reach those most in need. We cannot afford to allow the promise of hope to fade away and to leave people to despair."