German Chancellor Angela Merkel called for a renewed global consensus on humanitarian principles at a summit in Istanbul. She said attacks on hospitals in countries such as Yemen and Syria were "flagrant" violations of human rights conventions. Turkish President Recep Tayyip Erdogan said his country expects the burden of dealing with refugees to be shared more fairly.

German Chancellor Angela Merkel delivers a speech at the world humanitarian summit in Istanbul, Turkey, on May 23, 2016. The first world humanitarian summit opened here Monday with United Nations Secretary-General Ban Ki-moon urging governments, aid groups, the private sector and other stakeholders to act to improve the global humanitarian system. (Xinhua/Anadolu Agency)

"Germany supports the proposal to raise the volume of the central emergency response fund to one billion U.S. dollars. From the German side, we are going to spend more money on humanitarian aid. We need prepared crisis facilities and not only action when a catastrophe is happening," Merkel said.

"Turkey is the country hosting the most refugees in the world according to United Nations records. I am sure you are aware of how much of a burden it placed on us. On the other hand, Turkey did not receive the necessary contribution in this role (from the international community). We expect a fairer sharing of the burden on refugee issues," Erdogan said.

Turkey is sheltering nearly 3 million Syrian refugees at a cost of around 10 billion US dollars as a result of the Syrian civil war. The two-day UN summit in Istanbul seeks to develop a better response to what the UN has called the worst global humanitarian situation since World War Two. An estimated 130 million people now in need of aid.