president to consider. >> we're part of the interagency discussion about the incident and about options that may be available. >> reporter: any military cyber response will be coordinated with the fbi which is leading the investigation. >> we take it very seriously. we will respond proportionally, as i said. >> reporter: one potential, an offensive, u.s. military cyber attack on north korea's limited online capabilities. but it may be tough. >> we know from defectors from this unit called bureau 121 or unit 121, that they have 3,000, 5,000 cyber warriors. they operate out of china, singapore, europe, as well as using computer nodes throughout the world. >> reporter: oddly, experts who track online outages around the world are reporting internet routes into north korea since sunday have been down. no one is yet saying this is a u.s. counterattack.