The Government is "right not to pay ransoms" to extremist groups who kidnap British citizens, according to the Archbishop of York.
John Sentamu spoke to Good Morning Britain after IS released video footage claiming to show the murder of American journalist Steven Sotloff.
The Archbishop called on the United Nations to act to "make sure this barbaric activity does not continue".
I've been told at the Nato summit that the intelligence services know exactly who 'Jihadi John' is - or at least are 99.9% certain.
The British aid worker being held by Islamic State is David Haines, a 44-year-old father-of-two from Perth, Scotland.
In a video statement which claims to record his final words US hostage and journalist Steven Sotloff blames US foreign policy for his death.