According to North Korea's state-run KCNA, Pyongyang announced the "total success" of the test, which took place at 10:00 a.m. local time Wednesday as ordered by top leader Kim Jong Un.

　　United Nations Secretary-General Ban Ki-moon said the test was "deeply troubling."

　　"This act is profoundly destabilizing for regional security and seriously undermines international non-proliferation efforts. I condemn it unequivocally. I demand the DPRK cease any further nuclear activities and meets its obligations for verifiable denuclearization."

　　The top UN official denounced the test ahead of a UN Security Council emergency meeting.

　　朝鲜氢弹试验震惊国际社会

　　Elbio Rosselli, United Nations ambassador for Uruguay, which currently holds the rotating Council presidency, said after the meeting that the test is a clear violation of UN resolutions.

　　"The members of the Security Council also recall that they have previously expressed their determination to take further significant measures in the event of another DPKR nuclear test. And in line, with this commitment, and the gravity of this violation, the members of the Security Council will begin to work immediately on such measures in a new Security Council resolution."

　　China, a permanent member of the UN Security Council and a country which enjoys close ties with North Korea, due to proximity, responded harshly.

　　Foreign Ministry spokesperson Hua Chunying said China "firmly" opposes the latest nuclear test conducted by North Korea.

　　"China is steadfast in its position that the Korean Peninsula should be denuclearized and nuclear proliferation be prevented to maintain peace and stability in Northeast Asia. We strongly urge North Korea to honor its commitment to denuclearization, and to cease any action that may deteriorate the situation. The peace and stability on the Korean Peninsula and in Northeast Asia meet the common interests of all concerned. China is determined to advance denuclearization on the Korean Peninsula, and settle the nuclear issue through the six-party talks."

　　According to North Korea's official statement, the purpose of developing nuclear weapons is aimed against the United States' hostile policy toward the country.

　　The statement also said that Pyongyang would not resort to using nuclear weapons unless its sovereignty was infringed on

　　However Washington is expressing doubts, saying initial analysis from the US side indicates that the latest nuclear test is "not consistent" with a hydrogen bomb.

　　White House spokesman Josh Earnest reiterated the "rock-solid" commitment of the United States to the safety and security of South Korea and Japan.

　　"At this point what we want the North Koreans to do - when I say we, I don't just mean the United States, I mean our allies and our partners in the six party talks. We want the North Koreans to end their provocative acts, both in the form of missile tests and nuclear tests, to commit to denuclearization, and to demonstrate a commitment to pursuing peace and stability on the Korean peninsula."

　　On Wednesday, U.S. Defense Secretary Ash Carter and his South Korean counterpart Han Min-koo spoke by phone to discuss potential responses by the two countries.

　　The Pentagon said the two "agreed that any such test would be an unacceptable."

　　South Korean President Park Geun-hye convened an emergency security meeting right after the test on Wednesday, vowing to make North Korea pay a corresponding price

　　"Today North Korea pushed ahead with its fourth nuclear test. This is not only a serious provocation toward our security but is also a threat on our people's survival and future, and furthermore a direct challenge against global peace and safety. Until now, we and the international community have repeatedly warned that if the North goes through with a nuclear test, we will not overlook it and will make the country pay for its action."

　　Japanese Prime Minister Shinzo Abe also condemned the test, calling it a "significant threat."

　　In Brussels, the European Union described the test as "illegal and dangerous behavior."

　　Both France and Britain, among other countries, have issued condemnations of the nuclear test.

　　North Korea previously conducted nuclear tests in 2006, 2009, and 2013.

　　In response to these tests, the Security Council adopted several resolutions to strengthen sanctions on North Korea, which include an arms embargo, an embargo related to nuclear, ballistic missile, and a ban on the export of luxury goods.