The U.N. humanitarian chief says the international community has sent "record amounts" of aid to alleviate the fallout from the Syria crisis, but that it's hard to keep up with rising regional needs.

Stephen O'Brien spoke Saturday from the Zaatari camp for Syrian refugees in Jordan.

Some 4 million people have fled Syria since 2011, most moving to neighboring countries. Millions others are displaced within Syria. U.N. officials say aid money received so far covers 38 percent of the $7.4 billion requested for 2015.

O'Brien saying funding gaps are widening because of protracted conflicts, "even though we are securing record amounts of funding, record amounts of political will and support." He did not specify if funding has increased since migrants started flooding into Europe in recent weeks.