DHAKA: The US armed forces chief says Islamic State (IS) militants are being damaged by air strikes in Syria but air power alone is not enough to defeat them.

Gen Martin Dempsey said a political solution and a ground campaign would both be needed in Iraq and Syria.

Gen Dempsey said that up to 15,000 fighters - to be drawn from Syria's moderate opposition - would be needed for a ground force in Syria.

On Friday, the UK agreed to join US-led air strikes on IS in Iraq.

French fighter jets are already taking part in strikes in Iraq and Belgium and Denmark are also sending planes, reports BBC.

Speaking at the Pentagon, Gen Dempsey said this week's strikes in Syria had disrupted IS's command, control and logistics capabilities.

BDST: 1047 HRS, SEP 27, 2014