Obama says these militants pose a danger because they won't need a U.S. passport to make such a visit.
He tells ABC's "This Week" that the U.S. must improve surveillance, reconnaissance and intelligence gathering to neutralize the risk, and U.S. Special Forces are going to have a role. And he says military strikes against organizations that could do us harm may be utilized.
The nation has been under serious threat throughout his presidency from Europeans and certain others that embrace jihad. Obama says such militants have been gaining strength in some places.