The discussions at the border truce village of Panmunjom are the product of an agreement the two Koreas reached two weeks ago to end a dangerous military standoff and reduce cross-border tensions.
But given North Korea's past record of manipulating the reunion issue for leverage over the South, there is no guarantee the planned event -- only the second in five years -- will go ahead.
Today's talks were expected to focus on confirming a date and venue for the event, with the most likely outcome a reunion at the North's Mount Kumgang resort sometime in early October.
Most died without having a chance to see or hear from their families on the other side of the border, across which all civilian communication is banned.
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About 66,000 South Koreans -- many of them in their 80s or 90s -- are on the waiting list for an eventual reunion, but only several hundred can be chosen each time.
The reunion programme began in earnest after a historic North-South summit in 2000, and was initially an annual event.
But strained cross-border relations have allowed only one reunion in the past five years, with several being cancelled at the last moment by North Korea.
That number was reduced to 200 after interviews and medical exams, and the two Koreas drew up a final list of 100 each after checking if relatives were still alive on the other side.
For the lucky ones who do take part, the reunions are hugely emotional -- almost traumatic -- affairs, with many of the elderly participants breaking down and sobbing as they cling to each other.
The events typically last several days and the joy of the reunion is tempered by the pain of the inevitable -- and this time permanent -- separation at the end.