An ISIS fighter stands near burning confiscated cigarettes in the city of Raqqa April 2, 2014.

US defense chief Ashton Carter has said that an operation to isolate the ISIS in Syria’s Raqa should begin in conjunction with the assault on the extremists’ Iraqi bastion Mosul.

“We want to see an isolation operation begin around Raqqa as soon as possible,” Carter said during a visit to Iraq’s autonomous region of Kurdistan to review an ongoing offensive to retake Mosul from ISIS.

“We are working with our partners there (in Syria) to do that,” the US secretary of defence said, adding: “There will be some simultaneity to these two operations.”

Iraqi forces launched a huge operation last week to retake Mosul, the last major city in Iraq under ISIS control.

The loss of Mosul would leave Raqqa – the de facto capital of the extremists – the only major city still under ISIS control.

[vuukle]