HAGEL: ISIS IS 'BEYOND ANYTHING WE'VE SEEN. WE MUST PREPARE FOR EVERYTHING'

Secretary of Defense Chuck Hagel warned of the threat posed by militants from the Islamic State of Iraq and Syria (ISIS or ISIL), calling the group an "imminent threat" to "every interest we have."

"They are as sophisticated and well-funded as any group that we have seen. They're beyond just a terrorist group," Hagel said at a joint press briefing with Chairman of the Joint Chiefs of Staff Martin Dempsey.

Hagel added: "This is beyond anything we've seen. We must prepare for everything."

Hagel and Dempsey's briefing addressed the ongoing U.S. military campaign to aid Iraqi and Kurdish forces against ISIS militants in Iraq, as well as the group's brutal murder of American journalist James Foley and the failed attempt by U.S. forces to rescue him and other hostages.

The U.S. campaign in Iraq, Hagel said, remains limited in scope, and he said President Barack Obama has been clear about not allowing so-called "mission creep" with U.S. forces. But he said a long-term strategy is being pursued against ISIS, because the threat has clearly been established. Both he and Dempsey said ISIS must also be defeated in Syria as well as Iraq. Dempsey said it would be possible to "contain" ISIS, but not without going after the group in Syria.

"We continue to explore all options," Hagel said, when asked whether the U.S. would consider expanding the U.S. mission into Syria.

Both Hagel and Dempsey said U.S. airstrikes against ISIS have blunted the militants' advances. Dempsey said the U.S. has conducted nearly 90 airstrikes thus far. But Hagel said he expected ISIS will regroup and launch a new offensive in Iraq soon.