PARIS (AP) — Defense Secretary Ash Carter says the U.S.-led coalition is laying groundwork for the start of the operation to retake the Syrian city of Raqqa from Islamic State militants. Carter insists there is no delay in the operation.

Carter was speaking Tuesday alongside French Defense Minister Jean-Yves Le Drian after a meeting with 11 other defense chiefs to discuss the progress of the campaign to defeat the Islamic State group.

European leaders, including the French, have expressed worries that the battle to retake Raqqa hasn't begun yet. There are fears that IS leaders will continue to plot and inspire attacks, like the ones that rocked France and Brussels.in the past year.

Raqqa, in northern Syria, is an Islamic State stronghold, along with the Iraqi city of Mosul.