US Defense Secretary Ash Carter has called on Turkey to take a more active role in the fight against ISIS.
Carter added that Turkey as agreed, in principle, to send its planes on bombing missions, but that Ankara must still do more to control the border with Syria.
"It's a border over which logistics for ISIS and the fighters cross," he said. "So we're looking for them to do more in that regard as well and are in active discussions with them about that."