'Jihadi John': Emwazi was 'targeted in centre of Raqqa'

US Secretary of State John Kerry says the Pentagon is still assessing whether Emwazi was killed in the attack.

Speaking on a visit to Tunis, Kerry said: “We are still assessing the results of this strike.”

He told reporters extremists “need to know this: Your days are numbered, and you will be defeated.”

Joshi insists he has no insider information on whether the UK was given that option.

But the UK was at least involved in the planning of the drone strike in what a well-placed Whitehall source described as a “long, protracted operation”, according to the Guardian’s defence and security writer Richard Norton-Taylor.

It involved GCHQ interceptions from both intelligence-gathering aircraft and ground-based listening posts, alomsot certainly in Cyprus, as well as US spy planes, the source said.

But it also involved other parties in the “coalition” against Isis. The source made it clear he was referring to neighbouring countries, including Jordan.

He would not be drawn on whether these countries had “human sources”, ie informants, on the ground, but that was the inference.

There are no British special forces in northern Syria, the source insisted.