North Korea sent Monday an official notice to the South calling for dialogue but the South said it was nothing new and the North had to take responsibility for two attacks last year before talks could be held.

Tension on the Korean peninsula surged last year to the highest level since the 1950-53 Korean War after the sinking of a South Korean navy ship and a deadly exchange of artillery fire on the disputed maritime border between the Koreas.

After threatening the South with nuclear weapons last month, the North has made some conciliatory gestures, the latest of which was an official notice to the South calling for talks, the North's state-run KCNA news agency reported.

In response, the South's Unification Ministry, which handles relations with the North, said its neighbour had offered talks only to get financial support and aid, which it said was a typical tactic.

The North must acknowledge responsibility for the sinking of a South Korean warship and the deadly attack on Yeonpyeong island last year, as well as show sincerity on denuclearisation for talks to go ahead, the ministry said in a statement.

South Korea, a close U.S. ally, said the North sank the ship in March. The North denied that. In November, the North launched an artillery attack on the southern island, killing four people.

In its latest offer, the North suggested a round of working-level talks on January 27 and said it would reopen a Red Cross channel of communication over the border and a liaison office in a jointly run industrial park on the northern side of the border, KCNA said.