U.S. Pledges Nearly $500 Million In Humanitarian Aid For Victims Of Syrian Civil War

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ANKARA, Sept 12 (Reuters) - U.S. Secretary of State John Kerry announced on Friday nearly $500 million in humanitarian aid for people and countries hit by Syria's civil war.

The aid package includes more than $250 million "to assist refugees and host communities in the neighboring countries affected by the crisis," Kerry said in a statement.

Some 3 million Syrian refugees have registered in neighboring countries, according to the United Nations, but many remain trapped by the advance of Islamist militants or are having difficulty reaching open border crossings.

The U.N. refugee agency said two weeks ago that almost half of all Syrians had now been forced to leave their homes by the conflict, with 6.5 million thought to be displaced within Syria.

The highest concentrations of refugees in neighboring countries are in Lebanon (1.17 million), Turkey (830,000) and Jordan (613,000), according to UNHCR. Some 215,000 are in Iraq with the rest in Egypt and other countries. (Reporting by Jason Szep; Editing by Nick Tattersall)