North Korea's Kim says road blasts mark end of 'evil relationship' with South

Kim visited the headquarters of the 2nd Corps of the Korean People's Army on Thursday, where he reviewed defence plans following Pyongyang's recent decision to blow up road and rail links with the South, the official Korean Central News Agency (KCNA) said.

In his discussions with military commanders, Kim "stressed that our army should keep in mind once again the stark fact that the ROK is a foreign country and an apparent hostile country," KCNA said, referring to South Korea's official name, the Republic of Korea.

Relations between the two Koreas have deteriorated since Kim in January defined Seoul as his country's "principal enemy" and said the North was no longer interested in reunification.

On Thursday, state media had said the North's constitution now defines the South as a "hostile" state, the first time Pyongyang had confirmed the legal changes called for by Kim earlier this year.

The country last week held a key meeting of its rubber-stamp parliament, where experts had widely expected the constitution to be revised.

Cutting the road and rail links with the South, Kim said, "means not only the physical closure but also the end of the evil relationship with Seoul which persistently lasted century after century... and unreasonable idea of reunification," KCNA reported.

South Korea's military released video footage on Tuesday of North Korean soldiers dynamiting symbolic roads and railways connecting the two Koreas.

The detonations may have been done for domestic propaganda reasons, experts have said, with some pointing out that Pyongyang appeared to have used South Korean military images in its media coverage of the event.

Kim Yo Jong, the North Korean leader's powerful sister and a key regime spokesperson, reacted angrily on Friday to accusations by the South's military that its images had been used without copyright approval.

"I would like to inform those idiots of the fact that the photo is a screenshot from one of the video clips released by NBC, Fox News, Reuters and other foreign media," she wrote in a characteristically colourful press statement carried by KCNA.

"Their behaviour makes even a cat laugh," she added.