Secretary of State John Kerry said on Friday that the US would provide an additional $500 million in humanitarian aid to victims of the war in Syria, bringing total American assistance to $2.9 billion since the start of the conflict in 2011.
"This is the largest funding announcement made by the United States in response to the largest appeal the United Nations has ever issued," a statement said.
The announcement was made as Kerry arrived in Ankara as part of a regional tour to shore up support to combat Islamic State jihadists.