An employee of the Red Cross talks on the phone at the Korean Red Cross headquarters in Seou on Saturday. North Korea on Saturday indefinitely postponed reunions of families separated by the Korean War. They were set to start Wednesday. (Park Dong-ju/AP)

North Korea on Saturday ordered the indefinite postponement of a planned six-day reunion event for families divided by the Korean War, quashing a humanitarian program that the South had hoped could spur at least modest cooperation on the peninsula.

The reunion, due to start Wednesday, was to have been the first arrangement in three years, bringing together about 100 people from each side at a mountain resort just north of the demilitarized border. In nearly all cases, those selected for the event were to see relatives — siblings, spouses and children — for the first time in six decades.

The South on Saturday called it “inhumane” to call off the reunion and said that the North had “destroyed the hope” of long-separated family members, according to a statement posted on the Unification Ministry’s official Facebook page.

Han Jeong-hwa, 87, from the South Korean city of Busan, had already done her hair and bought new clothing. At Mount Kumgang, she was to reunite with her eldest son, now 66, whom she has not seen since he was 5.

“She is too disappointed to even speak about” the postponement, another of Han’s sons, Kim Hee-wook, who also lives in Busan, said by phone.

The North said Saturday that South Korean conservatives were leading a “vicious confrontation racket” unconducive to dialogue, according to a statement carried by its state-run news agency and attributed to the Committee for the Peaceful Reunification of Korea.

Pyongyang routinely makes such accusations. In this case, the North cited as evidence the recent arrest of a leftist South Korean lawmaker accused of plotting a pro-North rebellion. The lawmaker, Lee Seok-ki, in turn, has accused the South’s spy agency of leading an anti-communist “witch hunt.”

Still, top South Korean officials have spent recent weeks advocating closer ties with Pyongyang — provided the North’s third-generation leader, Kim Jong Un, proves himself worthy of trust. This month, the South’s unification minister, Ryoo Kihl-jae, said inter-Korean relations had entered a “phase of change” for the better, citing the family reunions and the reopening of a jointly operated industrial complex.

Since tensions spiked between the two Koreas in the spring amid a trade of war threats, both governments have pushed tentatively for rapprochement. But they have also been tripped up by even minor obstacles, canceling a high-level summit in June, for instance, when the sides could not agree on their respective representatives.

But restoring the family reunions — 18 of which were held between 2000 and 2010 — is a particularly urgent matter, South Korean officials say. Most of the survivors from the Korean War are now in their 70s or 80s. During the chaotic three-year war, millions moved from one side to the other — sometimes for financial or ideological reasons, sometimes just to seek safety. But the war ended with a 1953 armistice that created a near-impermeable border along the 38th parallel. Those below the border have almost no means of contacting those above it, barred from making phone calls or sending mail to the North.

Just this past week, one of the South Koreans selected for the reunion died. Three others said they could not make it because of deteriorating health, the South’s Unification Ministry said.

For those healthy enough, such as Park Tae-bong, 85, this reunion was supposed to be a chance to piece together decades of missing family history. He was set to reunite with one of his sisters. He also planned to learn more about his mother, who died in North Korea.

“We were hoping to hear about where her grave is,” said Park’s son, Park Jae-seung, who had planned to accompany his father to the resort.

Yoonjung Seo contributed to this report.