The former chief of the UN inquiry into North Korean human rights abuses decried North Korea's recent "wanton, useless, tantrum-driven" destruction of a joint liaison office Thursday, calling for South Korea to reconsider its "old strategy" toward the recalcitrant regime.

Michael Kirby, the former chairman of the UN Commission of Inquiry (COI) on Human Rights in North Korea, made the remarks during an online discussion organized by the civic group, the Committee for Human Rights in North Korea (HRNK).

"What I am hopeful of is when (President Moon Jae-in) saw the explosion and destruction of the wanton, useless, tantrum-driven destruction of the building in Kaesong for reunification dialogue, he may come to a conclusion that the old strategy has to be reconsidered," Kirby said, referring to the blowing up of the office in the North's border city Tuesday.

"The old strategy was adopted in the hope that it would result in the end to the actions of Kim Jong-un, but it hasn't," he added.

Taking umbrage at what the North claims to be the South's "connivance" of North Korean defectors sending anti-Pyongyang leaflets into its territory, Pyongyang demolished the office set up in September 2018 as a key symbol of cross-border reconciliation.

Kirby voiced hope that the demolition would serve as a "wake-up call" to the South Korean government and its people that "trying to appease this angry and autocratic government in North Korea doesn't work."

Touching on Seoul's move to take legal steps to prevent North Korean defectors from sending propaganda pamphlets into the North, Kirby said he is not sure whether "the best strategy is to punish those who try to speak the truth."

"If it is simply insulting material, that's one thing. But if it's based on the best possible available data, such as the material in the report of the COI, then bringing that to the people of North Korea is not wrong. It is right," he said.

But he called the method of sending the leaflets to the North in balloons "old-fashioned."

"Dropping down pamphlets is really a resort to 1930-1940 technology. And it was done because of the jamming and other interference, with digital technology getting into North Korea," the former Australia High Court judge said.

"I think the effort should be to build inter-Korean communication that will allow much freer expression to get into North Korea from South Korea. But as to whether it is lawful under the constitution for South Korea to stop it, well no doubt that has to be decided by those on the ground who know what is important for the safety of South Korea and North Korea," he added.

Commenting on the increasingly venomous rhetoric by Kim Yo-jong, the younger sister of the North Korean leader, Kirby said he was "not all that impressed" as she is part of the Kim family that has carried out "horrible things."

"It is by their deeds you have to judge the people. I am afraid somebody who has grown up in a life of privilege, in a life of a family which has such power in the land, power of life and death that has killed an uncle, Jang Song-thaek, and has killed a brother, Kim Jong-nam, and done all of these other horrible things," he said.

"People who have that power, until that power is removed from them, tend to use it. That is I think what we are seeing about the actions of Kim Yo-jong." (Yonhap)