My visit to the Dadaab refugee camp and a hospital for malnourished children in Wajir, Northern Kenya, today was both enormously upsetting and powerfully motivating. The women I met at Dadaab, their feet bloodied by weeks of walking to reach this refuge, told me harrowing stories of their journeys. Some had been robbed, others encountered violence. Some had even lost their children to hunger on the way.

But as terrible as their ordeal had been, those who reach the camp are in many ways more fortunate than those left behind. They are getting the health care, emergency feeding and water they so desperately need.

I am proud to say that many of those people are benefitting from the generosity of the British people. The funds raised by the DEC and other appeals show that when disaster strikes, Britain responds. The Government's package of assistance, on behalf of the British taxpayer, will also save thousands of lives. And after seeing the scale of suffering here, I am more determined than ever to ensure that every pound of our assistance delivers 100 pence of value.

But even with the help announced by Britain, there is a grave danger that thousands of children will die here in East Africa over the coming months. So where Britain leads, others must follow. Over the coming days and weeks, I expect many more pledges of support from countries around the world - and I will be actively urging them to put their shoulders to the wheel.

The international community - countries, UN agencies and non-governmental organisations - must now work together to prevent what is already a terrible crisis becoming a humanitarian catastrophe which engulfs this whole region of Africa.