By Alex Jensen

SEOUL

South Korea cautioned Tuesday that North Korea will be struck by an "unbearable" global punishment if it goes ahead with a plan to test a nuclear warhead and ballistic missiles.Earlier in the day, Pyongyang's state media unveiled leader Kim Jong-un's intention to carry out the tests soon.The threat was issued despite strengthened sanctions by the United Nations against the North following nuclear tests in January 2016 and a rocket launch a month later. Kim explained that "a nuclear warhead explosion test and a test-fire of several kinds of ballistic rockets able to carry nuclear warheads will be conducted in a short time," according to the KCNA news agency.The leader also boasted of having acquiredballistic missile re-entry technology, further enhancing the threat posed by North Korea to perceived enemies as far-flung as the United States. Kim previously claimed that his country had mastered the technology required to miniaturize nuclear warheads, while Pyongyang has made repeated threats against both the U.S. and South Korea amid their ongoing largest joint military drills to date.The South has expressed concerns about how far North Korea's nuclear technology has really developed, but sent a firm warning nonetheless."If North Korea directly challenges the international community's united resolve and conducts another provocation, it will face the international community's unbearable punishment and take the path to self-destruction," foreign ministry spokesperson Cho June-hyuck told reporters. Meanwhile, a South Korean lawmaker claimed that Pyongyang has been conducting its own exercises focused on realizing its stated plan to "liberate Seoul".The ruling Saenuri Party's Lee Cheol-woo was cited by local news agency Yonhap as pointing out that that the North's drills have focused on a replica of the South Korean capital. He added after a briefing by security officials that the defense ministry is already anticipating potential provocations at the tense border between the Koreas, who never signed a peace treaty after their 1950-53 conflict.