The floor leader of the ruling Democratic Party called Tuesday for reunions of separated families between South Korea and North Korea, saying it is the most urgent issue to address in expanding cooperation and exchanges between the two sides.

Rep. Woo Won-shik made the appeal as inter-Korean relations have shown signs of warming in the wake of North Korean leader Kim Jong-un's charm offensive toward the South, such as the country's participation in the PyeongChang Winter Olympics and the dispatch of his only sister to the South as part of a high-level delegation.

"The frozen hearts of our people toward the North are showing signs of a thaw," Woo said, referring to the recent warming of cross-border ties. "The most urgent issue in moving toward full-scale cooperation and exchanges is to hold separated family reunions and military talks."

Woo also said family reunions have long been considered a symbol of the status of inter-Korean relations and urged the North to show its sincerity about reconciliation with the South with an agreement to hold Red Cross talks to set up family reunions.

The issue of separated families is highly emotional and the most urgent humanitarian matter for the two Koreas, as more aging Koreans have passed away without having the chance to meet with their relatives on the opposite side of the tense inter-Korean border.

The two Koreas have held 20 rounds of face-to-face reunions involving some 19,800 family members from both sides. The last one was held in October 2015 at a facility on Mount Kumgang on North Korea's east coast.

From 2005-2007, video-based reunions were held on seven occasions, enabling about 3,750 people to see their long-lost relatives, according to the ministry.

South Korea has called for family reunions on a regular basis, urging the North to allow them to at least exchange letters. But Pyongyang has not responded to Seoul's calls. (Yonhap)