Meanwhile, Defense Secretary Chuck Hagel says North Korea's recent rhetoric presents are real and clear danger to the U.S. and its Asia Pacific allies.
And its push into VR—which Mr Zuckerberg sees as a stepping stone to augmented reality (AR), where information is superimposed on the real world—pits it against formidable rivals, too.
The backdrop is a barren landscape and it's unclear where the video was shot. US officials say they've seen it but aren't yet in a position to confirm its authenticity.