ABOARD A US MILITARY AIRCRAFT — Gen. Martin Dempsey said Sunday that once he determines the Islamic State militants in Iraq have become a direct threat to the U.S. homeland, he will recommend the U.S. military move directly against the group in Syria.

But the chairman of the Joint Chiefs of Staff said that right now, he still believes the insurgent group is still more a regional threat and is not plotting or planning attacks against either the U.S. or Europe.

Speaking on a military plane en route to Afghanistan, Dempsey provided more detail into his thinking about the Islamic militants who have stormed across Iraq, operating out of safe havens in Syria.

Dempsey did not rule out strikes for any other critical reasons, but listed a homeland threat as one of the key triggers for any military action in Syria.

So far, the Obama administration has restricted its military action against the militants to specific operations within Iraq, but concerns have increased as the Islamic State group extended its reach, taking control of a swath of land stretching from Syria across the border and deep into western and northern Iraq.