UN refugee chief says Syria 'mess' can't be fixed

"Massive support from the international community" is needed to deal with the Syrian refugee crisis, the UN High Commissioner for Refugees tells the BBC.

"We are no longer able to clean up the mess. The humanitarian capacity is not enough for the dramatic needs we are facing," Antonio Guterres said.

Since 2011, more than three million Syrians have fled their country as a result of the ongoing civil war. An additional 7.6 million have been displaced inside the country.

Guterres spoke to the BBC's Laura Trevelyan in Washington, DC, where he was meeting US officials to discuss the crisis.