Yoon Do-han, Cheong Wa Dae's senior secretary for public communication, speaks on Wednesday during a televised briefing at the South Korean presidential office regarding North Korea's bombing of the South-North joint liaison office on Tuesday. Yonhap

The office of President Moon Jae-in strongly condemned the sister of North Korean leader Kim Jong-un on Wednesday for her "rude and senseless" criticism of Moon and warned that it won't tolerate the North's unreasonable words and acts anymore.

"It is a senseless act to disparage (Moon's speech earlier this week) in a very rude tone without understanding its purpose at all," Yoon Do-han, Cheong Wa Dae's senior secretary for public communication, said in a war of words between the two Koreas.

Hours earlier, Kim Yo-jong, a powerful sister of the leader, launched an unusually harsh direct criticism of Moon over his remarks on inter-Korean relations earlier this week on the 20th anniversary of the historic Seoul-Pyongyang summit. Moon reaffirmed his unswerving commitment to a pair of 2018 summit deals with the North and called on its sitting leader not to reverse it.

Kim described Moon's comments as "shameless sophistry" and ridiculed his view.