The Head of the US Armed Forces says Islamic State militants are being damaged by airstrikes in Syria - but he says air power alone isn't enough to defeat them.

General Martin Dempsey says he will recommend sending US ground troops into Syria - if he believes it's necessary to win the fight against this terrorist organisation.

President Obama has repeatedly said he wouldn't send ground troops into combat - but General Dempsey says he can't rule out that option:

Meanwhile, Britain is preparing to launch its first airstrikes on Islamic State targets in Iraq, with RAF jets expected to take off as early as today.

Targets are now being selected after most British MPs voted to join the US led coalition.

Labour MP Pat McFadden was among those who backed the British Prime Minister.

But he thinks David Cameron should have gone further, to deal with Islamic State in Syria as well.