Grilled over whether he was advocating negotiations with ISIS, Mr Smith replied: “My view is ultimately all solutions to these sort of crises, these sort of international crises, do come about through dialogue.

“So eventually if we are trying to solve this, all of the actors do need to be involved. But at the moment ISIL are clearly not interested in negotiating.”

He added: “I‘m yes at some point, at some point for us to resolve this we will need to get people around the table.”