North Korea conducted its sixth nuclear test last Sunday in defiance of strong sanctions and warnings by the international community.
South Korea has vowed to take an even tougher response to the North, while the UN Security Council is pushing for more sanctions on the regime.
The Korea Meteorological Administration detected a magnitude 5.7 artificial earthquake at 12:29 p.m. Sunday around the North’s Punggye-ri nuclear site in North Hamgyeong Province. It was found to be the result of an underground nuclear explosion.
In what it called a “major announcement” issued at 3:30 pm, the North claimed to have “completely succeeded” in testing a hydrogen bomb that can be mounted onto an intercontinental ballistic missile (ICBM).
North Korean state media said the ruling party’s political bureau standing committee held a meeting Sunday morning chaired by leader Kim Jong-un and decided to conduct the test.
The latest test was the most powerful yet. Experts say a five-point-seven magnitude tremor would translate to an explosive yield of about 50 kilotons, which is at least five times greater than the fifth test last year.
The Sunday provocation was the fourth nuclear test under the Kim Jong-un regime. The North also fired ballistic missiles nine times since the Moon Jae-in administration came to power in South Korea.
Since conducting its first nuclear test in October 2006, the regime has rapidly increased the destructive power of its nuclear weapons. In its 4th test in early 2016, Pyongyang claimed success in testing a hydrogen bomb for the first time.
In response to the latest test, South Korea, the US, and Japan convened emergency National Security Council meetings and discussed countermeasures. Even China and Russia strongly blasted the North’s nuclear test.
To send a strong warning to the North, the South Korean military on Monday conducted a combined live-fire exercise involving the Hyunmoo 2A surface-to-surface ballistic missile and F-15K fighter jets.
While US President Donald Trump mentioned military options, his Secretary of Defense James Mattis said that though the U.S. is not seeking the total annihilation of North Korea, it does have the capability to do so.
During telephone talks, President Moon and President Trump also agreed to remove the limit on the maximum payload of South Korean missiles.
Meanwhile at the UN, the U.S. has proposed new tougher sanctions against North Korea, including an oil ban and a freeze on North Korean leader Kim Jong-un's assets.
The draft UN resolution calls for bans on supplying a range of oil products to the North and an end to hiring North Korean laborers and making payments to them.
Seoul, Washington and Tokyo are trying to persuade China and Russia, which oppose cutting oil supplies to the North, to back the proposed sanctions.
In South Korea, there are also growing calls for the deployment of tactical nuclear weapons.