North Korea claims it tested a hydrogen bomb that could be attached to an intercontinental ballistic missile (ICBM). Pyongyang said the test was a “perfect success,” and an artificial earthquake was detected in the region. The action was North Korea’s sixth nuclear test overall. Its neighbors, including China and Russia, condemned the nuclear test. “China's government expresses resolute opposition and strong condemnation toward this,” the Chinese foreign ministry said in a statement.