Nearly two full days after the explosion in North Korea, U.S. Officials, including Pentagon Spokesman Bryan Whitman, cannot say for sure whether it was a nuclear explosion or not.

• 朝鲜发生爆炸事件近两天后,包括五角大楼发言人布赖恩。威特曼在内的美国官员都无法确定这是否是一次核爆炸。