Seoul, Jan 06 (Agencies): South Korea has dismissed a North Korean call for unconditional talks to ease tensions, saying on Thursday the offer was "propaganda" it does not take seriously.

The North's gesture on Wednesday came as the United States met Chinese and South Korean officials for talks about how to calm the Korean peninsula and persuade the North to stop its nuclear work.

US envoy Stephen Bosworth is in China on Thursday and will be in Japan for talks on Friday. Washington is pressing Beijing to do more to rein in its ally North Korea.

"North Korea previously issued statements like this early in the year ... they are normally done as part of propaganda campaign toward the South," a Unification Ministry official said.

The artillery fire and the March 2010 sinking of a South Korean ship blamed on the North despite its denials, have raised tension in Asia and increased the pressure to resume talks.

Analysts say Pyongyang's military aggression and unveiling of a previously-undisclosed nuclear enrichment facility are ways of raising the stakes ahead of six-party talks, a forum in which it has previously won substantial aid.

Although both Koreas have called for dialogue to solve the crisis, the South, like Washington, is loath to be seen rewarding the North's actions with the talks and concessions it desires.

"Whether this (North-South) exchange is a sincere step back from the brink or simply a pause before a new round of tension is still uncertain," Abraham Kim and Jack Pritchard from the Korea Economic Institute wrote in a note.

Pyongyang walked out of the aid-for-disarmament talks with the South, United States, Russia, Japan and China in 2008. It has since expelled UN atomic monitors and conducted a second nuclear test.

"We call for an unconditional and early opening of talks between the authorities having real power and responsibility," a statement said.

The United States suggested the North must first stop provoking its neighbour, recommit to a 2005 nuclear pact and take responsibility for recent attacks.

The South Korean official said the North was using the statement for domestic purposes and that Pyongyang needed to convince the outside world that it was serious.

"…North needs to show, not simply by making offers for dialogue, that it is genuine in its intentions, in the wake of the series of events that have taken place."