Nauert pointed out that the Security Council adopted the resolution with a unanimous vote with China and Russian Federation, expressing hope that the two nations will faithfully implement the new sanctions.
This yield is close to what 38 North previously estimated to be the maximum containable yield for the test site in Punggye-ri, northeastern North Korea, it added.
Xenon is a naturally occurring, colorless gas that is used in manufacturing of some sorts of lights.
The agency says it couldn't verify exactly what kind of nuclear bomb the North detonated as it hasn't found several other radioactive isotopes that typically accompany a nuclear explosion. It also referred to South Korea as "traitors and dogs" of the US.
North Korea's sixth nuclear test at the Punggye-ri Nuclear Test Site was so powerful that it caused part of the mountain to crumble, triggered substantial landslides, and displaced more than 85 acres, Jeffrey Lewis, the director of the East Asia Nonproliferation Program at the James Martin Center for Nonproliferation Studies, wrote on the Arms Control Wonk site. The analysts gave no indication that a test appeared to be imminent.
Prior to the test, North Korean state media released images of the warhead it intends to mount on its new Hwasong-14 intercontinental ballistic missile. The North Korean statement also called for the breakup of the U.N. Security Council, calling it "a tool of evil" and comprised of "money-bribed" nations. China and Russian Federation share the view that the Kim regime will not give up its nuclear programme without security guarantees. In comparison, radar images of last year's nuclear test did not show a noticeable change in the surface area of the same mountain, she said. "If I want to send the most compelling message, I have been persuaded that the triad in its framework is the right way to go", Mattis said.
However, after facing the problem with first tunnel, the North authorities shifted to the second mountain: Mount Mantap for rest of the five nuclear tests, including the latest one in September.
A pre-emptive strike against Pyongyang's leadership would be hard to undertake, but it's widely seen as the most realistic of the limited military options Seoul has to deny a nuclear attack from its rival.
Information for this article was contributed by Choe Sang-Hun of The New York Times and by Kim Tong-Hyung, Hyung-jin Kim and Robert Burns of The Associated Press.