A sweeping purge of senior North Korean negotiators since the failed Hanoi summit with the U.S. in February has brought talks with the regime to a grinding halt.

An intelligence source said Thursday that the purge is probably the reason the North has been so quiet in talks with South Korea. It has severely thinned out the ranks of the departments tasked with negotiating with the U.S. and South Korea.

That means denuclearization talks between the U.S. and the North will probably be put on hold for some time until halfway competent replacements for the purged officials have been found.

Several key officials appear to have been punished. Among them is Kim Yong-chol, Kim Jong-un's erstwhile right-hand man who oversaw preparations for the summit and has been sent to a labor camp. A worse fate befell Kim Hyok-chol, the top negotiator who was reportedly executed by firing squad.

Kim Song-hye from the United Front Department was also sent to a prison camp. Ri Son-gwon, the chairman of the Committee for the Peaceful Reunification of the Fatherland, who had been the main contact point with South Korea since last year, is also rumored to have been purged. Although Ri was not involved in the failed Hanoi summit, he had been a close aide to Kim Yong-chol for years.

One North Korean defector who used to be a senior official in the North said, "The purges targeting high-ranking officials are likely to result in changes in the regime's South Korea policy. There'll be no significant inter-Korean dialogue until we see an outline of the changes."

The South Korean government has been pushing for another cross-border summit, but there has been no response from the North. No meetings have taken place at the new liaison office in the North Korean border town of Kaesong since the Hanoi summit.

North Korean leader Kim Jong-un said in a speech last month that he expects talks with the U.S. to resume at the end of this year. Pundits believe that means he wants to give himself time to put another negotiating team together.

[Read this article in Korean]