The UN High Commissioner for Refugees, António Guterres, has said that the amount of money received by aid agencies to date covers just 28% of the estimated demand.
He said the UN estimates that $2.9 billion (£1.9bn) are needed - in addition to $2 billion (£1.3bn) outstanding from earlier pledges - to meet the humanitarian need in Syrian and surrounding countries.
Aid agencies have received just $840 million (£540m) to date.
Half the population at the Zaatari refugee camp are children. After escaping violence at home they are now growing up on the edge of war.
In my second special report, I see how charities in Zaatari are working with Syrian children to try to numb the painful trauma of war.
Zataari, a Syrian camp for more than 100,000 refugees, is a place so desolate that only the truly desperate would call it home.