SEOUL (Reuters) - North Korea on Saturday ordered the indefinite postponement of a scheduled series of reunions for families divided since the 1950-53 Korean War, dealing a setback to months of efforts to improve ties between the Korean neighbors.
Six days of meetings between family members still separated six decades after the war had been due to start on Wednesday in the Mount Kumgang resort, just north of the militarized border.
They had been seen as a step in furthering months of thaw in chilled relations compounded by the North's refusal to abandon its nuclear program, described as its "treasured sword".
South Korea said the pullout by Pyongyang "broke the hearts" of Koreans grieving for relatives they were unable to see.
Jang Choon, a South Korean who had been looking forward to meeting his surviving brother and sister from across the border and had bought them lots of presents, said his feelings at the unexpected news could not be put into words.
"I cannot describe how I feel now, what else I can do?" the 82-year-old told Reuters at his home. "But I will not give up the hope of meeting my brother and sister some day."
The North's Committee for the Peaceful Reunification of Korea accused the South of poisoning dialogue, in a statement carried by the KCNA news agency. 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 reunions would have been the first in nearly three years.
North Korea also said it was putting off planned talks on resuming tours of Mount Kumgang, suspended after a North Korean guard shot dead a South Korean tourist in 2008. The talks had been set for October 2
South Korea's Unification Ministry said North Korea's change of heart was "very regrettable".
"North Korea should be criticized for its inhumane behavior that broke the hearts of all families separated by the war and of all South Koreans in general," ministry spokesman Kim Eui-do told a briefing.
The neighbors remain technically at war, as the 1950-53 war ended in an armistice rather than a peace treaty. The conflict left millions of families divided, with travel across the border all but impossible and nearly all forms of communication barred.
The abrupt announcement upended an easing of tension in recent months.
The two sides this week reopened a jointly-run industrial complex just over the border in the North that Pyongyang authorities had shuttered during weeks of high tension in April.
Yang Moo-jin, a professor at Seoul's University of North Korean Studies, said Pyongyang authorities were trying to secure more concessions from the South, in a recurrent tactic. Concessions this time, he said, were aimed particularly at lucrative tourism to Mount Kumgang.
"This is intended to urge the South Korean government to take a clear stance on Mount Kumgang tours," said Yang. "For North Korea, the tours come first and family reunions come later. It is the opposite for South Korea."
At the height of the 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 after the North conducted its third nuclear test in February.
The North also denounced weeks of joint South Korean military exercises with the United States.
Tension has since waned, although a U.S. research institute and a U.S. official this month said satellite imagery suggested North Korea had restarted a research reactor at its Yongbyon nuclear complex.
Additional reporting by Jack Kim; Editing by Ron Popeski and Clarence Fernandez