The UN has appealed for a record $16 billion to fund its humanitarian operations in 2015, with almost half the total going to help victims of the Syrian conflict.
It says the money will provide aid for more than 57 million of the most vulnerable people around the world.
The UN humanitarian chief said the level of need was “unprecedented”.
The request comes as aid agencies warn they are running out of cash to fund this year’s operations in Syria.
Last week the World Food Programme announced it would have to cut food rations to Syrian refugees.
It is seeking another $4.4 billion to help more than 3,250,000 Syrian refugees registered in neighboring countries.
“The rising scale of need is outpacing our capacity to respond,” said UN Undersecretary-General for Humanitarian Affairs Valerie Amos.
“The crises in Central African Republic, Iraq, South Sudan and Syria will remain top humanitarian priorities next year.”
Valerie Amos said those conflicts accounted for more than 70% of the funding being sought.
Other major crises covered by the appeal include Afghanistan, DR Congo, Myanmar, Palestinian territories, Somalia, Sudan, Ukraine and Yemen.
However, the UN said it did not include nine countries in Africa’s Sahel region, which will be addressed in a separate request in February.
UN High Commissioner for Refugees Antonio Guterres said: “This is not business as usual in the humanitarian world. Today’s needs are at unprecedented levels, and without more support there simply is no way to respond to the humanitarian situations we’re seeing.”
Food and medical supplies for refugees have to be purchased in advance, and field hospitals have to be delivered and built.