U.S. Defense Secretary Ash Carter says that even as Iraqi forces advance on Mosul in Iraq, the coalition fighting Islamic State militants is laying the groundwork for another operation against the group, in its stronghold in nearby Raqqa, Syria.
"Yes, there will be overlap,” Carter said. “And that is part of our plan and we are prepared for that. There is no delay. This is proceeding on plan, just as Mosul is proceeding on plan."
Carter spoke at a news conference alongside French Defense Minister Jean-Yves Le Drian, who said taking Mosul from IS would have a major effect on the terrorist group in terms of resources, organization, management and leadership.
Mosul is particularly symbolic, because IS leader Abu Bakr al-Baghdadi announced his self-proclaimed caliphate during a 2014 speech in the city.
But Le Drian warned that the coalition must destroy what he called the Islamic State's virtual caliphate along with its territorial one. He also said it is difficult to pin down movements of IS forces between Mosul and Raqqa and other besieged cities.
Earlier, French President Francois Hollande also warned of terrorists hiding among streams of people trying to escape Mosul.
The United Nations has said the Islamic State may have massacred scores of people around Mosul as Iraqi and Kurdish forces advance on the city.