The UK is to give £100m ($124.3m) each in overseas aid to South Sudan and Somalia to help alleviate famine conditions.
International Development Secretary Priti Patel has called on the global community to step up their support for the two nations as she announced the cash injections for 2017-8.
The Department for International Development said parts of South Sudan were now in famine, adding that in 2017 there was a credible risk of another three famines in Yemen, north-east Nigeria and Somalia.
The extra funding will help provide food, water and emergency healthcare which is hoped will save more than a million lives.
Quote Message: The world faces a series of unprecedented humanitarian crises and the real threat of famine in four countries. These crises are being driven by conflict and drought and we must respond accordingly. Our commitment to UK aid means that when people are at risk of dying from drought and disaster, we have the tools and expertise to avoid catastrophe. In times of crisis, the world looks to Britain not just for our work on the ground, but also for our leadership internationally." from UK International Development Secretary Priti Patel
The BBC's diplomatic correspondent James Landale says the problem is that these crises have been caused as much by conflict as by drought.
And no amount of aid will end the violence that has brought so much suffering to these countries, he says.