"We are going to defeat Daesh. We always said it will take time," Kerry said, using an alternative name for the Islamist militant group.
"We began our fight against al Qaeda in 2001 and it took us quite a few years before we were able to eliminate Osama bin Laden and the top leadership and neutralise them as an effective force,” he told reporters.
“We hope to do Daesh much faster than that and we think we have an ability to do that.”