Media playback is unsupported on your device Media caption John Cantlie was kidnapped in Syria in 2012

A third video has appeared featuring British hostage John Cantlie who is being held by Islamic State militants.

The journalist delivers a scripted message responding to US President Barack Obama's recent speech on the anniversary of the 9/11 attacks.

The script mocks the US's strategy of employing air power combined with local ground forces.

Mr Cantlie appears sitting at a desk against a black backdrop, following the same format as in previous videos.

Further messages

The message ends with a comment by him that Islamic State (IS) says it welcomes meeting with what is described as President Obama's under-construction army.

There are no signs of violence in the video but in the first of these messages Mr Cantlie made clear he was speaking as a prisoner whose life was in danger.

At the end of the five-and-a-half minute film he indicates there will be further messages.

The video comments on Mr Obama's speech: "It was all disappointingly predictable; America is good, the Islamic State is bad; and they will be defeated using aircraft and a motley collection of fighters on the ground. For their part the Islamic State say they welcome meeting Obama's under-construction army."

Image copyright Other Image caption Mr Cantlie as he appears in the video

The experienced journalist and photographer has twice been held captive in Syria.

He was kidnapped in July 2012, and handcuffed and blindfolded for a week, but escaped with the help from the Free Syrian Army.

A second kidnap happened when he returned to Syria towards the end of 2012.

Aid mission

Islamic State - also known as Isis or Isil - has taken control of large areas of Syria and Iraq and declared a caliphate.

Since August, IS has filmed and posted online the deaths of three Western hostages who were beheaded.

They were US journalists James Foley and Steven Sotloff and British aid worker David Haines.

In the video showing the killing of Mr Haines the militants threatened to kill British hostage Alan Henning.

Mr Henning, a taxi driver from Eccles in Salford, was seized while on an aid mission to Syria in December.

Meanwhile, RAF planes based in Cyprus are continuing to fly missions, but it is not thought they have engaged in combat.

The first RAF jets to take part in operations against IS carried out armed reconnaissance at the weekend.

Parliament has voted by 524 votes to 43 to take action against IS in Iraq.