We'll help America destroy Isis, pledges David Cameron
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 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.
The decision to invite Labour's interim leader Harriet Harman to a National Security Council briefing on the threat last week was seen as a further step to prepare the ground for a possible parliamentary vote to extend air strikes in the autumn.
But ministers will also be forced to explain why RAF pilots were allowed to take part in bombing raids over Syria despite MPs having voted against Britain carrying out strikes in the country.
Downing Street has confirmed that Mr Cameron was aware of the missions flown by a small number of aircrew embedded with US and Canadian forces, despite Parliament only authorising attacks on IS targets in neighbouring Iraq.
Asked directly in an interview for US television channel NBC if he planned to join the US-led air raids within Syria, he said: "Look, we know that we have to defeat Isil, we have to destroy this caliphate, whether in Iraq or in Syria.
"I want Britain to do more. 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 to destroy the caliphate in both countries," he told the Meet The Press programme to be broadcast today.