The UK's Department for International Development (DFID) is to provide £200m in emergency aid to South Sudan and Somalia. Christian Aid has welcomed the news, but the former Archbishop of Canterbury has urged that millions of people are 'on the edge of survival'.

The new government package announced today will provide water, food and healthcare support to the millions presently starving and dying in the regions. Earlier this week a famine was declared in parts of South Sudan and a crisis of starvation continues in Nigeria and Yemen.

Christian Aid's Head of Humanitarian Nick Guttmann said: 'The International Development Secretary Priti Patel is right to say the world's response to these unprecedented crises has been inadequate. Whether it's Yemen, South Sudan, Somalia or Nigeria, the magnitude of suffering is unlike anything we've seen for a long time. Yet, for too long these humanitarian disasters have gone unnoticed, underreported and underfunded.

'That is why we are delighted that the UK Government is sending a strong message to the world, that it's high time we "step up our support". If more funding comes quickly – including to local NGOs – and if agencies can get access to remote areas, then the spread of famine could be averted in South Sudan.'

Through its local partners, Christian Aid has provided humanitarian support to hard-to-reach areas of South Sudan. However, Guttmann said that more still needs to be done. He said: 'Hundreds of millions of pounds are still needed if we are to prevent further catastrophe. We can only hope that the international community does not ignore its duty – not only to fund the aid response, but also to stick with communities for the long haul and help them address the root causes of the emergencies we are seeing today.'

The former Archbishop of Canterbury, Rowan Williams, is the chair of Christian Aid. He called the famine declaration in South Sudan 'another horrific blow to the hopes and security of the people of this war-ravaged country, already coping with huge levels of displacement as well as violence'.

'Christian Aid has long been stressing the urgency of the situation, and, with this latest announcement, we hope that the attention of the world's governments and peoples will be drawn again to South Sudan,' he said.

'The crisis in South Sudan is just one of a number of humanitarian catastrophes the world is facing. Millions more are on the edge of survival – in countries like Somalia, Yemen and Nigeria – and we must continue to do what we can to help our sisters and brothers in dire need.'

Christian Aid has launched a South Sudan Crisis Appeal to fundraise in support of the region. Dr Williams urged support for the charity's appeal.

He said: 'The country desperately needs peace and stability; it also needs immediate practical support, and the Christian Aid appeal is a chance to respond to this, for the sake of a generation of South Sudanese whose hopes have been cruelly betrayed in the conflict and barbarity of the last few years.'