The United States still cannot say for sure the underground detonation was a nuclear blast; the working assumption is that it was, but not very successful, the official said.

• 美国现在还不能肯定的说这次地下引爆是一次核爆炸。目前的假设是它是核爆炸，但不是一次成功的核爆炸，这名官员说。