Ban said he had noted Pyongyang's calls for dialogue, but added that "any meaningful dialogue should be firmly anchored in the denuclearisation of the Korean Peninsula", in comments released by the UN during a trip to China.

He urged North Korean authorities "to fully comply with the relevant Security Council resolutions with the aim of realising the denuclearisation of the Korean Peninsula".

North Korea, which has carried out three underground nuclear tests since 2006 and has also defied the international community with rocket launches, is under heavy UN-sponsored sanctions.

A visiting North Korean official expressed willingness Wednesday to rejoin long-stalled talks aimed at the country's denuclearisation, China's foreign ministry said, the second time in a month Pyongyang has told Beijing it is ready for such dialogue.

The North's first vice foreign minister Kim Kye-Gwan made the remark on a trip to Beijing on Wednesday, the ministry said in a statement, but offered no concrete details.

Tensions have run high on the peninsula since the North's third nuclear test in February which triggered new UN sanctions that ignited an angry response from Pyongyang, including threats of nuclear attacks on Seoul and Washington.

Ban, a former South Korean foreign minister, repeated calls for discussions on the issue, "particularly through dialogue between South and North Korea, who are the directly concerned parties," he said.

Tempers have cooled in recent months amid indications Pyongyang may be adopting a less confrontational stance.

North Korea on Sunday offered to hold talks with the US, who replied that preconditions for such talks have not been met.

Pyongyang, however, abruptly cancelled a planned meeting with South Korea shortly before reaching out to Washington.

Ban has met with high-ranking officials including President Xi Jinping during his trip to China.

"I expressed my sincere appreciation to the Chinese president and also asked him to continue to play a constructive role and to first of all reduce tension and facilitate a dialogue between South and North Korea," Ban said.