South Korea and China will discuss ways to bring North Korea back to dialogue, the South's nuclear envoy said Wednesday, after Pyongyang shunned Seoul and reportedly test-fired a missile.

Wi Sung-Lac was later Wednesday to start a two-day visit to China, the North's sole major ally, to discuss ways to resume six-party nuclear disarmament talks stalled since December 2008.

Efforts to revive them have been complicated by tensions on the Korean peninsula, which have worsened again lately.

Last week the North test-fired a short-range missile off its west coast in the first such launch for 19 months, South Korean sources told AFP Wednesday, The launch was seen as a routine test to improve the country's missile capability, the sources said without elaborating.

Media reports said a KN-06 missile, with a range of 100-110 kilometres (62-68 miles), was fired into the Yellow Sea.

Wi, who will meet his Chinese counterpart Wu Dawei Thursday, said regional powers had agreed a three-step approach.

This calls for the North to hold talks with the South and then meet the United States before the full nuclear forum -- also grouping Russia, Japan and China -- reopens.

"We will first make efforts to revive a dialogue channel between the South and the North," Wi was quoted as telling Yonhap news agency.

Pyongyang last week declared it would no longer talk to Seoul's conservative government which it denounces as traitors bent on confrontation.

"The present conservative 'government' is a pro-US one installed by the US and a marionette regime acting under its wire-pulling," the North's ruling party newspaper Rodong Sinmun charged Wednesday.

Defying diplomatic norms, Pyongyang last week also disclosed apparent secret approaches from Seoul for summit talks.

And its military has threatened retaliation unless Seoul punishes troops who used pictures of Pyongyang's ruling dynasty as rifle-range targets before the practice was banned.

At a secret meeting in Beijing last month, the North said, Pyongyang rejected calls for summits after Seoul's representatives repeated demands for an apology for two deadly border incidents last year.

The South accuses the North of torpedoing a warship in March 2010 with the loss of 46 lives, a charge it denies.

Last November the North killed four people including civilians with a bombardment of a South Korean border island. It says its neighbour provoked the barrage by test-firing shells into the North's waters.

"The overall mood is not good, but there is room for diplomacy to play a role," Wi said.

"During the visit to China, I will learn about why North Korea made such a stance public and discuss from every angle how to cope with the current situation."

The North fuelled regional security fears last November by disclosing a uranium enrichment plant, which could give it a second way to make atomic bombs.

Pyongyang says it is willing in principle to restart the six-party forum on ending the nuclear programmes in return for diplomatic and economic benefits.

But it has not said whether it is willing to discuss its atomic programmes with the South, an approach it previously rejected.