Islamic State fight: Cameron says UK will 'play its part'

David Cameron has said Britain is ready to "play its part" in fighting Islamic State, which he called an "evil against which the whole world must unite".

Speaking at the United Nations in New York, the UK PM said "past mistakes" must not be an "excuse" for inaction.

He spoke as US and Arab jets continued bombing Islamic State (IS) targets in Syria, after attacks began on Tuesday.

The UK cabinet will discuss plans for air strikes against IS in Iraq later, with Parliament due to vote on Friday.