Cameron offers to help US ‘destroy’ IS

David Cameron pledged to help America “destroy” self-styled Islamic State (IS) extremists in Syria as he gave his clearest signal yet that UK forces could be asked to join air strikes.

The British prime minister said he wanted Britain to “step up and do more” if he could secure the approval of parliament as he prepared to issue a stark warning to home-grown would-be jihadists that IS wanted them as “cannon fodder”.

He will use a speech today to set out what aides said would be “significant” elements of the government’s strategy to combat the threat from fundamentalist terrorism for the next five years.