LONDON, ENGLAND - NORTH Korea renewed its criticism of South Korean President Lee Myung Bak, accusing him of 'rude behaviour' and saying he could not be negotiated with.

The North's official KCNA news agency on Monday quoted a spokesman for the Committee for the Peaceful Reunification of the Fatherland (CPRF) reacting to an interview Mr Lee had given to Japan's Kyodo News.

The North appears to have interpreted comments made by Mr Lee to mean that the issue of the North's nuclear disarmament ought to be discussed at North-South summit talks, despite this problem being at the centre of international six-party talks.

'It is absolutely intolerable to overturn the north-south declarations ... it is rude behaviour,' KCNA quoted the unnamed CPRF spokesman.

'It is quite clear that it is impossible to sit at the negotiating table with such a man.'

Mr Lee, elected last December, has adopted a tougher stance towards Pyongyang than his predecessors. His attitude has already triggered harsh comments from the North Koreans.

North Korea's first mention of Mr Lee, who took office in February, referred to him as a 'political charlatan', an 'absent-minded traitor' and a 'US sycophant'.

The two Koreas are technically still at war following a 1953 ceasefire.

Topics covered at the 2000 and 2007 summits included aid and investment by South Korea in North Korea, an agreement to connect their railways and for visits for families split by the Korean War.

It is thought the nuclear issue was not discussed.

The six party talks, that comprise the two Koreas, the United States, China, Japan and Russia, look to offer North Korea economic and diplomatic incentives for dismantling its nuclear programme.

Last month, as part of the nuclear disarmament agreement, North Korea blew up the cooling tower at its plutonium-producing reactor in a symbolic show of its commitment to the deal. -- REUTERS