"In accordance with the decision taken by the North Korean leadership, the North Korea ministry of foreign affairs has begun preparing a fourth round of negotiations (...) for mid-July," said the North Korean diplomatic source in China, quoted by the Russian news agency Interfax.

South Korea's Unification Minister Chung Dong-Young held a rare meeting in Pyongyang on June 17 with reclusive North Korean leader Kim Jong Il in a bid to jumpstart the stalled six-way talks aimed at ending Pyongyang's nuclear weapons programme.

North Korea has boycotted the talks, which also include the United States, South Korea, Russia, Japan and China, for more than a year citing a "hostile" US policy following three inconclusive rounds.

The nuclear standoff flared in October 2002 when Washington accused Pyongyang of operating a nuclear weapons programme based on enriched uranium in violation of a 1994 agreement.

On February 10 this year, North Korea announced it had nuclear weapons.