North Korea accused Seoul on Friday of intentionally dragging ties on the unstable peninsula to a new low, with a former South Korean leader saying relations may now stand on the brink of reconciliation or catastrophe.
Analysts said the North, closing its few border crossings and refusing to let international inspectors remove samples from a plutonium-producing plant, was retreating deeper into its shell amid growing speculation over the health of leader Kim Jong-il.
They say that the North is seeking instead to turn the focus onto the South and its conservative President Lee Myung-bak, who cut off what once had been a free flow of unconditional aid when he took office in February and tied future handouts to the North's denuclearisation.
North Korean mouthpieces have turned up the heat this week on Lee, who they label a traitor.
"Lee Myung-bak's group doesn't want either dialogue or unification. What they want is to intentionally worsen the North-South relationship," the North's Minju Joson newspaper said in a commentary.
Pyongyang also is furious at Lee's government for letting civic groups send anti-Kim leaflets across the border.
