Younger South Koreans worry that merging the countries would crush their successful society.
South Korea has dismissed an "incomprehensible" list of demands by North Korea for reviving suspended operations at a jointly-run industrial park.
North Korea has issued new threats against South Korea, vowing "sledge-hammer blows" of retaliation if the its southern neighbour did not apologise.
Pope Francis, in his first Easter Sunday address, has called for a diplomatic solution to the crisis on the Korean peninsula.
North Korea leader Kim Jong-un has urged troops to be on alert for a potential war, media reported, in its latest response following UN sanctions.
South Korea's President Park Geun-hye has called for North Korea to walk away from nuclear weapons and take the "peace and shared development" path.
North Korea has slammed a display of Christmas lights staged by a South Korean church group near the border as an "unacceptable provocation".
Cheap rates and zen seating: spiritual tourism has taken off in South Korea, offering foreigner and tourists alike a taste of temple life.
South Koreans have lit a Christmas tree-shaped tower near the tense border with North Korea for the first time in two years.
Some of the South Korean Christian aid workers held hostage by Afghanistan's Taliban said they were beaten for refusing to convert to Islam and protecting female captives, a hospital chief said on Monday. "We found through medical checks that some male hostages were beaten," Cha Seung-Gyun told reporters.
Nineteen newly freed South Korean hostages were set to fly out of the Afghan capital on Friday after a six-week kidnap drama, sources close to the arrangements said, after a deal critics fear could spur more abductions. Taliban insurgents freed the remaining seven South Korean Christian volunteers late on Thursday.
Taliban insurgents will release 19 South Korean Christian volunteers they have been holding for more than a month in Afghanistan, South Korea's presidential Blue House said on Tuesday. The announcement followed the resumption of negotiations that had been on hold for two weeks.