(CNN) -- The first military talks between South Korea and North Korea ended without progress Thursday, the Yonhap news agency reported.
Seoul demanded that Pyongyang apologize for the sinking of a warship in March, which killed 46 South Korean sailors, a ministry official said, according to Yonhap.
The working-level military talks were held at the truce village of Panmunjom on the Korean border and lasted for about two hours.
South Korean officials "strongly urged North Korea to admit to, apologize for and punish those responsible for the attack on the Cheonan warship," Seoul's defense ministry said in a statement, according to Yonhap.
North Korea has denied sinking the warship.
The South also demanded that North Korea "immediately stop its military threats and aggressive behaviors at sea borders," the statement said.
The two sides did not set a date for the next round of talks, Yonhap reported.
At the start of Thursday's talks, North Korea's lead negotiator called for a "humanitarian view" in dealing with issues proposed by the two Koreas, Yonhap said, referring to a pooled newsgathering report.
"All issues should be resolved from the point of a humanitarian view at today's talks," North lead negotiator Col. Ri Shin-kwon was quoted as saying in the pooled report.
The South Korean lead negotiator sounded a cautious note.
"We will watch how your side deals with those issues," said Col. Moon Sang-kyun, according to the pooled report.
Pyongyang had asked to discuss the two countries' de facto sea border on the west coast. North Korea wants the border, known as the Northern Limit Line, redrawn farther south.
Deadly naval clashes between North and South took place along the Northern Limit Line in 1999, 2002 and 2009.
North Korea also wanted to discuss a South Korean plan to fly anti-Pyongyang leaflets into the North, in response to the sinking of the South Korean warship in March. South Korea has since deferred the leaflet plan.
The communist North's proposal was met with skepticism. Military officials in South Korea say the North tends to act provocatively, then follow with proposals to talk and try to win concessions, Yonhap said.
The two Koreas are technically still at war, because the 1950-53 Korean War ended without a peace treaty. North-South relations remain tense.
In recent weeks, Pyongyang also has proposed temporarily reuniting Korean families separated by war.
The Korean War divided millions of families. About 10,000 people applied to take part in a similar reunion last year, but fewer than 200 families were allowed to participate.