Seoul: North and South Korea ended their first working-level military talks in two years on Thursday with no progress as the meeting stumbled over the deadly sinking of a South Korean warship blamed on Pyongyang, Seoul`s Defence Ministry said.
The rare encounter came hours after Pyongyang vowed to strengthen its nuclear deterrent in response to what it called US threats.
A team of international investigators concluded in May that a North Korean torpedo sank the Cheonan warship near the two Koreas` western disputed sea border in March, killing 46 sailors. North Korea denies involvement and has threatened war if it is punished for the disaster.
On Thursday, South Korea pressed North Korea to immediately admit to and apologise for the sinking and to punish those responsible, the ministry said in a verbal statement after the talks in the Demilitarized Zone that divides the peninsula.
"North Korea`s responsible measures over the sinking of the Cheonan are a key to resolve the issue," the ministry said.
South Korea also urged the North to halt military threats and provocations near the disputed western sea border, as well as the North`s slander of South Korean authorities, the ministry said.
The poorly marked western sea border, drawn by the United Nations at the end of the 1950-53 Korean War, is a constant source of tension between the two Koreas.
Seoul has repeatedly rejected the North`s long-standing demands that the sea border be changed. The navies of the two Koreas engaged in three bloody skirmishes near the area in 1999, 2002 and 2009.
North Korea responded that it cannot accept the result of an international investigation and reiterated its long-standing demand that its own investigators be allowed to sent to South Korea to examine the results.
The North also called on the South to rein in activists who spread anti-North Korean leaflets. Pyongyang also claimed that South Korean Navy vessels regularly violate the western sea border.
The North said the inter-Korean relations depend on how South Korea handle the two issues, according to the ministry.
At the United Nations, North Korea`s Vice Foreign Minister Pak Kil Yon said on Wednesday that Pyongyang would continue to expand its nuclear arsenal in order to deter what it perceives as American and South Korean aggression in the region.
"As long as the US nuclear aircraft carriers sail around the seas of our country, our nuclear deterrent can never be abandoned but should be strengthened further," Pak said.
The North has routinely issued similar announcements. The latest one came after North Korean leader Kim Jong Il this week promoted his youngest son, Kim Jong Un, to a four-star general and also gave him key political posts aimed at an eventual succession.
Kim Jong-Il took over the communist country in 1994 after the death of his father, the North`s founder Kim Il Sung.
The talks also come as South Korea and the US hold naval drills in the Yellow Sea off the west coast of the Korean peninsula, near where the South Korean ship sank.