The official KCNA news agency accused the South's conservative government of trying to use the nuclear security summit, to be attended by US President Barack Obama and other world leaders, to take up the North's nuclear programme.

"If there is any provocative act such as the issuance of a so-called statement concerning 'the North's nuclear issue' at the Seoul conference, it would constitute an extreme insult" to the North's deceased leaders who left the denuclearisation as their final wishes, it said in a commentary.

"Taking part in traitor Lee Myung-Bak's devilish act would only worsen the situation on the Korean peninsula all the more," it said, referring to the South's president who will chair the meeting.

"Any provocative act would be considered as a declaration of war against us and its consequences would serve as great obstacles to the talks on the denuclearisation of the Korean peninsula," it said.

The North has previously blasted the summit as an "unsavoury burlesque" intended to justify an atomic attack by South Korea and its ally the US.

South Korea says the meeting will focus on ways to safeguard atomic material worldwide and prevent acts of nuclear terrorism.

Seoul officials say North Korea's nuclear programme is not on the agenda but the summit may build momentum towards denuclearisation.

The North's official media frequently refers to the likelihood of war breaking out on the peninsula.