North Korea vows to punish South Korean official

 (AP) — North Korea warned Tuesday that a South Korean official would pay a high price for saying the North "must disappear soon" in an escalation of rhetoric between the rivals.

South Korean Defense Ministry spokesman Kim Min-seok made the remark during a briefing Monday, when he said that North Korea wasn't a real country and existed for the benefit of only one person — a reference to dictator Kim Jong Un. He said the North has no human rights or public freedoms.

North Korea's government-run Uriminzokkiri website on Tuesday called Kim's comments a "grave provocation," and said that the country would "mercilessly" punish anyone slandering its top leader and the system.

"We will not sit idle by while this mad dog keeps ... barking noisily," the website said. "Kim Min-seok would severely pay the price for his thoughtless remarks."

Kim's comments followed a series of slurs by North Korea against the leaders of South Korea and the United States. Pyongyang's state media likened South Korean President Park Geun-hye to an "old prostitute" and President Barack Obama to a "monkey" in recent dispatches.

South Korea has been highly critical of North Korea's nuclear and missile programs, including recent rocket and missile tests and apparent preparations for a fourth nuclear test. But the comments from Seoul on Monday are stronger than usual. South Korea tries to avoid publicly talking about anything that could be interpreted as a collapse of the North Korean government because of worries that Pyongyang would raise tensions.

Pyongyang has been ramping up its rhetoric against Seoul and Washington since Obama and Park met in Seoul last month. During that visit, Obama said that it may be time to consider further sanctions against North Korea and that the U.S. will not hesitate to use its military might to defend its allies.

South Korea has called the North's verbal insults against Park immoral and unacceptable. The U.S. State Department described the North's racist slurs against Obama as "disgusting."