Former top US general in nuclear warning

As North and South Korea say their Olympic athletes will march under one flag, the former US Joint Chiefs of Staff says he fears we are closer to military conflict in the Korean Peninsula than we ever have been.

Admiral Mike Mullen also warned that Americans haven't had an honest conversation about what nuclear conflict really means and they underestimate how terrible it would be.

Media playback is unsupported on your device
Media caption"I just don't see anything moving in the right direction"