North Korean leader Kim Jong Un's younger sister on Sunday condemned South Korea for escalating military tensions, after the South's defense minister made remarks about its ability to strike against the North.

Calling the minister, Suh Wook, a "senseless and scum-like guy," Kim Yo Jong said in a statement carried by the official Korean Central News Agency that his "rhetoric about the 'preemptive strike' has further worsened the inter-Korean relations."

Kim Yo Jong. (Photo courtesy of Korea Media)(Kyodo)

"South Korea may face a serious threat owing to the reckless remarks," said Kim, vice department director of the Central Committee of the Workers' Party of Korea.

Kim, a close aide to the North Korean leader, added that Seoul "should discipline itself if it wants to stave off disaster."

The strongly-worded statement from Kim, who is known to have a strong influence over inter-Korean affairs, came ahead of the launch of a new South Korean government led by conservative President-elect Yoon Suk Yeol next month.

The defense minister said Friday that South Korean troops have the capability to "accurately" strike firing sites for North missiles as well as command and support facilities if there are clear signs of a launch toward the South.

The two Koreas remain technically in a state of war as the 1950-1953 Korean War, in which U.S.-led U.N. forces fought alongside the South against the North supported by China and the Soviet Union, ended in an armistice, not a peace treaty.