"We think there's an opportunity here to accelerate this campaign to put more pressure on this campaign against ISIL [Daesh]. This is the conversation we're having with our Turkish partners," Cook told reporters. "We are talking to all our coalition partners."
Cook explained the administration of President Barack Obama, which leaves office on January 20, felt a sense of urgency to take advantage of current opportunities to roll back Daesh in Syria as well as Iraq.
"Speed matters here: We want to move quickly… We've got ISIL [Daesh] under pressure. We want to move forward… We’re having a conversation to find the best and most effective way to0 conduct the most effective campaign against ISIL," he said.
Cook also announced further progress by the Iraqi army in its battle to retake the city of Mosul from Daesh. He said Iraqi forces had connected their different ground lines of advance into the city and had been backed by eight US-led coalition air strikes in the past 24 hours.
Cook also said that US-backed rebel forces in Syria were also continuing to advance towards Raqqa north and west of the city.
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