The U.S. military said it had air-dropped arms to Syrian rebels fighting Islamic State militants near Kobani on Sunday in what appeared to be the Pentagon's first public acknowledgment it has delivered lethal aid to the rebels.

The U.S. Central Command said it had delivered weapons, ammunition and medical supplies to the Syrian rebels who for weeks have sought to stave off an onslaught by Islamic State fighters that have overrun vast swaths of Syria and Iraq this year.

The "resupply" of rebel fighters is the latest escalation in the U.S. effort to help local forces beat back the radical Sunni militant group in Syria after years of trying to avoid getting dragged into the more than three-year Syrian civil war.