South Korea says military talks aimed at easing rising tensions with North Korea collapsed Wednesday, when the two sides could not agree on an agenda for a next round of negotiations.
Colonels from both sides met in the border village of Panmunjom for the first time since the North's deadly artillery shelling of a South Korean island in late November.
The meeting had been aimed at arranging higher-level military talks -- but the North Koreans walked out and no date was set for the next round.
Officials said the North refused to accept the South's demand for an apology for the November artillery barrage against Yeonpyeong Island. Seoul also wants an apology for the torpedoing of a South Korean warship last year that it blames on the North.
North Korea denies any role in the Cheonan sinking, which claimed 46 lives, and claims that South Korea provoked the incident.
The breakdown of Wednesday's talks dimmed prospects for a thaw in relations. But officials did not rule out the possibility an agreement on future talks could still be reached.
The Yeonpyeong attack prompted a series of South Korean military exercises -- including joint maneuvers with the United States that pushed tensions on the peninsula to their highest level in decades.
Hopes for improved relations rose Tuesday when South Korea agreed in principle to a North Korean suggestion that Red Cross officials from the two sides resume dialogue on humanitarian issues, including a resumption of reunions for families that have been separated since the Korean War ended in 1953.
Successful military talks between the two Koreas might have also cleared the way for a resumption of six-nation negotiations on North Korea's nuclear weapons program.
The six-party talks are aimed at getting Pyongyang to end that program in return for diplomatic and economic concessions.