North Korea's new leadership, highly critical of South Korea since taking power, published an unusual open questionnaire to its rival on Thursday, demanding answers to show that Seoul was sincere about resuming inter-Korean dialogue.

South Korea has reached out to its reclusive neighbour since the death of the state's leader Kim Jong-il last December in the hope of persuading Pyongyang to suspend its nuclear programme and return to regional aid-for-disarmament talks.

John Delury of Yonsei University said the North was trying to call South Korea's bluff on its willingness to engage, saying some of the demands would be dismissed as ludicrous in Seoul.

Analysts also said the North was also trying to influence voters in presidential and parliamentary elections in the South this year, by portraying the ruling conservatives as impeding improved relations on the divided peninsula.

The policy department of the North's National Defence Commission ran the questions on the state KCNA news agency, saying the South should make clear its aims on resuming dialogue.

The Policy Department of the DPRK (North Korea's) NDC solemnly urges them to answer the following open questions as they loudly trumpet about a resumption of North-South dialogue and improvement of relations, the Council said in the dispatch.

The questions related to denuclearisation, joint U.S.-South Korea military drills, two deadly attacks on the South in 2010, psychological warfare and the need to conclude a peace treaty to replace an armistice which ended the 1950-53 Korean war.

Under its new supreme commander Kim Jong-un, the North has denounced President Lee Myung-bak's administration as a group of confrontational maniacs and moral imbeciles.

South Korea has dismissed the remarks as vitriol, and insists it is ready to talk, even stating it will consider a resumption of food aid if its impoverished rival returns to the negotiating table.

In a separate and more extended KCNA item, the commission laid out the course of action for Seoul to take.

It urged the Lee administration to stop talking about North-South dialogue and improved relations and think again whether it has qualifications to be a dialogue partner of the DPRK, referring to the North by the initials of its official name.

SOUTH SAYS WILL NOT RESPOND TO QUESTIONS

South Korea's Unification Ministry, which handles relations with the North, said in a statement that it would not respond to the questions. It urged the North to take dialogue seriously.

Last month, the North slammed the door shut on talks with the conservative government in Seoul, but analysts said the questions from the National Defence Commission, which controls the powerful military, showed there was still hope for engagement.

If the South Koreans can say 'yes' to five of these nine questions, which they actually probably could, then you could see this as a kind of olive branch toward resuming some sort of indirect dialogue, said Delury of Yonsei University.

Relations between the two Koreas soured when Lee won office in 2008. He cut off all economic aid to the North, demanding Pyongyang's complete denuclearisation for the resumption of aid, which amounted to around $4.5 billion the preceding decade.

The questionnaire appeared a day after Washington's top diplomat for East Asian affairs, Kurt Campbell, said there was still hope for diplomacy on the peninsula, but insisted the path to broader regional talks must start with improved inter-Korean relations.

North Korea, which has twice tested an atomic device, walked out of international nuclear disarmament talks in 2009.

(Additional reporting by Jack Kim)