South Korea lashed out at North Korea Thursday for slandering its President Park Geun-hye, urging the communist state to stop resorting to vulgar invective and immediately come out for dialogue instead.

In recent weeks, Pyongyang has hardened its rhetoric against Park as she criticized the North’s provocative moves, including its recent underwater test of a submarine-launched ballistic missile and woeful human rights conditions.

Seoul, along with Washington and Tokyo, has also moved to strengthen pressure and sanctions against Pyongyang, triggering an angry response from the North. The reclusive state called Park a “rare wicked woman” and “a loyal dog of a (U.S.) colony” in a white paper published Wednesday.

“It is very regrettable that the North has defamed the head of state representing (South Korean) people,” said an official at Seoul’s Unification Ministry, declining to be named.

“We call on North Korea to stop the slander that does not help the two Koreas reopen bilateral dialogue. We also call on it to respond to our calls for talks and move out onto the path of inter-Korean development and reunification.”

Amid the exchange of harsh words, observers raised the possibility that the isolated country could set off provocations unexpectedly in a show of force and displeasure rather than coming forward for dialogue.

The North has used blatant words to attack Park in a series of commentaries in its state media including the Rodong Sinmun, the daily of the ruling Workers’ Party; the Korean Central News Agency; and the Minju Joseon, a newsletter for the North’s cabinet.

On Thursday, Uriminjokkiri, a propaganda website run by the North’s Committee for the Peaceful Reunification of the Fatherland, criticized Park’s visit to the U.S., slated for June 14-18, saying that it would undermine the preparation of an inter-Korean ceremony in Pyongyang to mark the 15th anniversary of the so-called June 15 inter-Korean declaration.

“(Park’s visit to the U.S.) will be a perilous gambling that puts the security of the Korean Peninsula and the region at risk,” the website said in its commentary.

Meanwhile, Seoul’s chief nuclear envoy Hwang Joon-kook and his U.S counterpart Sung Kim flew to Beijing Thursday to hold separate bilateral talks with China’s point man on North Korea’s denuclearization, Wu Dawei.

Their trip to China came the day after they held a trilateral meeting with their Japanese counterpart Junichi Ihara in Seoul to discuss the escalating nuclear threats from the North.

Their talks with the Chinese envoy are expected to focus on stressing China’s responsibility in addressing North Korea’s nuclear issue and coordinating a joint response to its enhancement of nuclear capabilities including the technology to develop an SLBM.

By Song Sang-ho (sshluck@heraldcorp.com)