Defense Secretary James Mattis said U.S. forces are using “annihilation tactics” in their fight against the Islamic State.

“We have already shifted from attrition tactics where we shove them from one position to another in Iraq and Syria to annihilation tactics where we surround them,” Mattis said on CBS’ ‘Face the Nation.’ “Our intention is that the foreign fighters do not survive the fight to return home to north Africa, to Europe, to America, to Asia, to Africa, we are not going to allow them to do so. We are going to stop them there and take apart the caliphate.”