Image copyright AFP Image caption David Cameron has urged EU leaders to adopt a "comprehensive approach"

The UK is to commit another £100m to supporting refugees in camps bordering Syria, David Cameron has said, as he arrived for an emergency EU summit on the migration crisis.

The prime minister said £40m of the additional cash would go to support the underfunded World Food Programme.

Separately, £7m will be spent helping migrants travelling through Greece, Italy and the western Balkans.

The meeting comes amid a dispute over a mandatory EU refugee relocation plan.

Europe is struggling to deal with a vast influx of migrants and refugees reaching the continent - most fleeing conflict in Syria but large numbers also fleeing violence and poverty in Afghanistan and Eritrea.

On Tuesday, EU interior ministers agreed a mandatory plan to relocate 120,000 migrants across Europe, despite opposition from some countries.

The UK has opted out of the quota system but has agreed to take in 20,000 refugees from the camps bordering war-torn Syria over the next five years.

Arriving in Brussels for the meeting of 28 leaders, Mr Cameron called for more support for vulnerable people in Syria and the wider region.

'Dangerous journey'

The UK has already provided £1bn in aid to Syria and Mr Cameron said the extra cash - to be given to the UNHCR, UNICEF, the UN Relief and Works Agency and the International Red Cross - would help thousands of people displaced by the conflict.

"We must make sure that people in refugee camps are properly fed and looked after but also to stop people wanting to make or thinking of making this very, very difficult and very dangerous journey to Europe".

Image copyright AFP/Getty Images Image caption Greece has been at the forefront of the migrant crisis, with thousands of people arriving on its islands every day

He added: "What Europe needs more than ever is a comprehensive approach to this migration crisis. We need to do more to stabilise the countries and regions from which these people are coming."

The UK's latest aid package also includes £14.5 million in new funding to provide assistance and protection in countries that refugees and migrants are leaving from and transiting through, including help for those already in Europe.

Of this:

£4m will go towards provide life-saving assistance and protection in Europe, including Greece and Italy

£3m will be spent on aid to migrants and refugees and support to governments in managing registration in the western Balkans

£3m will be spent on providing assistance and counselling to displaced people across Africa

£2m will be given specifically to Libya to provide, among other things, food, clean water and other essential goods through the Red Cross

£2.5 million to support systems for better understanding and predicting trends in population movement

International Development Secretary Justine Greening said the UK was helping to meet the most "immediate, basic needs" of displaced Syrians while also giving "immediate, life-saving humanitarian assistance to refugees in transit".

"The UN is desperately underfunded and more help is urgently needed in the short term," she said.

Earlier on Wednesday, Foreign Secretary Philip Hammond said the migration crisis in Europe "plays directly" into issues around the UK's renegotiation of its EU membership and was "focusing attention" on the challenges large-scale migration across the EU presented.

EU migration is one of the issues the government wants to address in its renegotiation of Britain's membership.