Billed as the first of its kind, the United Nations summit aims to develop a better response to what has called the worst humanitarian crisis since World War Two, mobilize more funds and agree to better care for displaced civilians.

UN Secretary-General Ban Ki-moon called on governments, businesses and aid groups to commit to halving the number of displaced civilians by 2030. "We need to improve more direct funding to local communities and fix the persistent humanitarian funding gap," he said in a speech.

"We are here to shape a different future," he told the gathering of 150 countries including 57 heads of government.

Canada pledged US$274 million in funding to UN agencies to help victims of natural disaster and armed conflict, with a focus on protecting women and children in war zones.

German Chancellor Angela Merkel said there needed to be improvements in how humanitarian aid is delivered.