North Korea on Saturday ordered the indefinite postponement of a scheduled series of reunions for families divided since the Korean War, dealing a setback to months of efforts to improve relations between the neighbours.
The six-day meetings of families torn apart by the 1950-53 war had been due to start on Wednesday in the Mount Kumgang resort just north of the militarised border.
They had been seen as an element in furthering months of thaw in chilled relations compounded by the North's refusal to abandon its nuclear programme, described as its "treasured sword".
The North's Committee for the Peaceful Reunification of Korea, in a statement carried by KCNA news agency, accused the South of poisoning dialogue. It said it could never tolerate Seoul misusing such dialogue to heighten conflicts.
"The reunions of separated families and relatives between the North and the South will be postponed until there can be a normal atmosphere where dialogue and negotiations can be held," said a spokesman for the committee, which oversees ties with South Korea.
The planned family reuions would have been the first in nearly three years.
The North's abrupt postponement came amid an easing of tensions. The two sides this week reopened a shuttered jointly-run industrial complex just inside the North, shut down by Pyongyong authorities during weeks of high tension in April.
North Korea issued daily threats to engulf both South Korea and its ally, the United States, in a nuclear war in response to new U.N. sanctions against Pyongyang.
The Security Council adopted the punitive measures in response to the North's third nuclear test in February.
But tensions have since waned, although a U.S. research institute and a U.S. official this month said that satellite imagery suggested North Korea had restarted a research reactor at its Yongbyon nuclear complex.