The UN refugee agency's chief has renewed a call on all nations to keep their borders open to Syrians fleeing their country, saying Syria's neighbors should not be "left alone" to cope with the influx, the Associated Press reports.

More than 2 million people have been uprooted from their homes in Syria's civil war, many scattered in refugee camps and informal settlements dotting neighboring Lebanon, Jordan, Turkey and Iraq.

UNHCR High Commissioner Antonio Guterres said during a meeting with officials from countries neighboring Syria Friday that the international community needed to assume "a true attitude of burden-sharing."

Guterres said: "It is unacceptable to see Syrian refugees drowning and dying in the Mediterranean Sea or being pushed back from borders."