South Korea on Thursday accepted North Korea’s offer of high-level military talks to ease months of tension, but said the North must admit responsibility for two deadly border attacks.

The offer came earlier in the day in a message from defence minister Kim Yong-Chun to his counterpart in the South, Kim Kwan-Jin.

Seoul’s unification ministry said the North suggested that the two sides exchange views on both incidents and on “military tension reduction” on the peninsula.

The ministry, which handles cross-border affairs, made clear it was sticking to its terms for dialogue that the North accept responsibility for the two attacks and show sincerity about nuclear disarmament.

“We will come to the high-level military talks, whose agenda should include the North’s making a firm commitment to taking responsible measures concerning the sinking of the Cheonan and the shelling on Yeonpyeong island,” spokeswoman Lee Jong-Joo told AFP.

She said the South agreed to the North’s proposal for working-level preparatory talks.

“As the North did not mention our demand as to denuclearisation, we will also separately propose high-level government talks to verify their seriousness about denuclearisation.”

Cross-border relations worsened sharply when South Korea last May accused the North of torpedoing one of its warships, the Cheonan, with the loss of 46 lives, a charge Pyongyang denies.

Tensions rose even higher after the North bombarded a South Korean border island in November, killing four people including civilians and briefly sparking fears of all-out war.

The North said it was responding to the South’s artillery drill on the island near the disputed border, which dropped shells into what the North claims as its waters.

In an abrupt change of tack this year, the North has repeatedly been calling for talks, but Thursday’s offer was the first proposal for a high-level meeting.

It came a day after US President Barack Obama and his Chinese counterpart Hu Jintao Wednesday in a summit statement agreed that “sincere and constructive dialogue” between the two Koreas was essential.

The North has previously baulked at talking about its nuclear programme with the South, saying it was designed to deter US attacks and should be discussed with Washington. Its disclosure last November of an apparently functioning uranium enrichment plant a potential second way to make atomic bombs heightened security fears.

Obama and Hu expressed concern at the “claimed” uranium enrichment programme. They called for the “necessary steps” to restart stalled six-nation nuclear disarmament talks grouping the two Koreas, Japan, Russia, the US and China.