North Korea renewed a threat Thursday that a South Korean official would pay a dear price for allegedly insulting North Korean leader Kim Jong-un, in the latest verbal tit-for-tat between the rival Koreas. It's not unusual for the communist country to issue harsh rhetoric, but this time the North pointed an accusing finger at South Korean defense ministry spokesman Kim Min-seok over his recent comments calling for the end of the North Korean regime. "It would be a mistake to think that Kim Min-seok, already our target, can escape the strike zone of justice," the North's official Korean Central News Agency said in a commentary, though it did not elaborate. The commentary also warned that those who criticize North Korea and Kim Jong-un will pay a dear price. The North's latest warning came three days after Kim, the ministry spokesman, called for the end of the North Korean regime, saying it perpetrates lies and exists only for one person, referring to young North Korean leader Kim Jong-un. "North Korea is not a proper country. There's no human rights, no freedom in that country. It exists only for one person.... Therefore, it must go away quickly," Kim said Monday in a regular press briefing. It is very rare for a South Korean official to publicly call for the end of the North Korean regime. The spokesman made the comments after North Korea denied responsibility for a trio of small drones found crashed recently on the southern side of the heavily fortified border separating the two Koreas. On Tuesday, North Korea's powerful National Defense Commission, headed by Kim Jong-un, threatened to wipe out those seeking to topple the North "in the most merciless and thorough strike."    The North has bristled at any outside criticism of its leader and has made several military threats against the South over alleged slander in recent years, though it has yet to follow through on its threats.