On 6 January 2016 at 10:00:01 UTC+08:30, North Korea conducted an underground nuclear test at its Punggye-ri Nuclear Test Site, approximately 50 kilometres (30 miles) northwest of Kilju City in Kilju County. The United States Geological Service reported a 5.1 magnitude earthquake from the location; the China Earthquake Networks Center reported the magnitude as 4.9.
North Korean media made announcements that the regime had successfully tested a hydrogen bomb, which had been claimed to have existed the month before the test was carried out. However, third-party experts, as well as officials and agencies in South Korea, doubted North Korea’s claims, and contend that the device was more likely to have been a fission bomb such as a boosted fission weapon. Such weapons use hydrogen fusion to produce smaller, lighter warheads suitable for arming a delivery device such as a missile, rather than to attain the destructive power of a true hydrogen bomb.
North Korea (officially the Democratic People’s Republic of Korea, or DPRK) had previously conducted three underground nuclear tests in 2006, 2009, and 2013, drawing sanctions from the United Nations Security Council. The presidents of the United States and South Korea urged North Korea to rejoin the six-party talks in October 2015. The presidents also warned North Korea against a fourth nuclear test.
In December 2015, North Korean supreme leader Kim Jong-un suggested that the country had the capacity to launch a hydrogen bomb, a device of considerably more power than conventional atomic bombs used in previous tests. The remark was met with skepticism from the White House and South Korean officials. In a New Year’s Day speech, Kim Jong-un warned that provocation from “invasive outsiders” would be met with a “holy war of justice”.
North Korean claims
The North Korean government described the test as a “complete success” and characterized it as self-defense against the United States. Korean Central Television (KCTV), the North Korean state-owned media channel, said that “the U.S. has gathered forces hostile to [the] DPRK and raised a slanderous human rights issue to hinder [the] DPRK’s improvement. It is [therefore] just to have [an] H-bomb as self-defense against the U.S. having numerous and humongous nuclear weapons. The DPRK’s fate must not be protected by any forces but [the] DPRK itself.” Ri Chun-hee, the television news anchor who announced the deaths of Kim Il-Sung and Kim Jong-Il, emerged from retirement to announce the H-bomb test to both the domestic and international audience.