David Cameron told US TV network NBC he wanted the UK to do more but said he needed to "take Parliament with him".

MPs voted against proposed military action in Syria two years ago.

Lord Richards, former chief of defence staff, called for a new strategy to defeat IS, saying he suspected ground troops would be deployed in the future.

Mr Cameron is due to use a speech on Monday to warn young Britons tempted to join IS fighters they will end up as little more than "cannon fodder".

"If you are a boy, they will brainwash you, strap bombs to your body and blow you up. If you are a girl, they will enslave and abuse you," he will say.

'Standard practice'

Speaking about the UK's possible role in fighting the group, Mr Cameron told NBC: "I want Britain to do more. I'll always have to take my parliament with me.

"We're talking and discussing at the moment, including with the opposition parties in Britain, what more we can do. But be in no doubt, we're committed to working with you to destroy the caliphate in both countries."

-BBC