David Cameron has urged an “emergency response” to the crisis as he sets out the extra money up to 2020. Funding will be used to help African countries cope with economic pressures, environmental disasters such as droughts and problems of corruption.
The money, announced during the Valletta summit on migration, will also be used to provide humanitarian support for refugees.
Ethiopia which has seen its refugee population soar from 90,000 in 2011 to 700,000 in 2015 will be provided with £125 million.
Some £5m will be used to provide life-saving humanitarian assistance in the Sahel countries such as Mali and Burkina Faso, with the money providing food, water and shelter.
As part of the drive to tackle the root causes of the problem, a £13m programme will create 9,000 jobs in Somalia, giving them the option of choosing to “stay where they are and not be coming to Europe”.
But as well as the extra funding for African nations, the government will also urge them to do more to accept the return of migrants who have tried to enter the EU illegally.
“The prime minister will be emphasising to the Africans that they have got to work with us on returns. We welcome the co-operation they have shown so far but it’s very important that we develop the situation where we are able to return illegal migrants who arrive in the Mediterranean,” a government source said.
The UK will also provide €3m (£2.1m) to a trust fund for Africa being set up by the European Commission.
Extra support for Africa came after Mr Cameron vowed the UK will play a “huge and historic role” in helping to tackle the migration crisis, including stepping up efforts to “smash” gangs of human traffickers.
The Prime Minister said it was “the biggest problem facing Europe today”, with a movement of people greater than any seen since the end of the Second World War.
He said: “We need to smash those gangs and that is what the next stage of this work is going to be about. It will be difficult work but it’s absolutely essential and we will give you everything you need to make sure that work gets done properly.”
In addition to the funding the EU has come up with a plan to help reduce the number of migrants – pressing African leaders into taking back thousands of people refused asylum. Officials announced a plan to expel some refugees who do not qualify for asylum and give them papers to fly to Africa, calling on African countries to let the migrants travel onwards to their homes.
A top African Union official called the idea “unheard of” and migration experts said it represents a sign of desperation.
The special “laissez passer” travel documents for Africans without ID are aimed at easing their return. In essence, it means the EU would decide where a person without a passport has come from in Africa – tantamount to the EU designating the nationality of someone on behalf of his home country.