The United Nations says up to 3 million people will need food, crop and livestock assistance within the next year in Syria, where a 17-month uprising has forced thousands to flee their homes.

The U.N. Food and Agriculture Organization says about half of those who are vulnerable will need immediate food assistance, within the next three to six months.

The assessment by the U.N. agency and the World Food Program Thursday says Syria's agriculture sector lost $1.8 billion this year as a result of the uprising.

In a separate development, U.S. President Barack Obama approved an additional $12 million in humanitarian assistance to Syria on Thursday. The White House says the money will be used for food, medical supplies and hygiene kits.

Australian Foreign Minister Bob Carr urged the world not to “neglect” Syria and its “refugee crisis.” He commented shortly before visiting Syrian refugees in Jordan on Thursday. Australia has donated more than $16 million in humanitarian aid to Syria.