Pyongyang's official Committee for the Peaceful Reunification of Fatherland (CPRF) said Mr Lee had in effect declared 'a war of aggression against the North", and vowed to sternly deal with the move.

'The CPRF strongly condemns the crazy remarks by the traitor Lee Myung-Bak, which declared a war of aggression against the North as its final goal,' the committee said in a statement carried by Pyongyang's official Korean Central News Agency (KCNA).

It branded Mr Lee's statement 'an unpardonable, anti-national crime that drive inter-Korean relations into catastrophe'.

'Now that there remains no room for us to talk about inter-Korean relations and the reunification issue with the Lee clique, it has become clear what our option should be,' it said.

As the Lee government continues pursuing 'the extremely dangerous path for confrontation,' it said, the North 'will strongly deal with it'.

Mr Lee, who has been on a trip to the United States, Brazil and Peru, reportedly told journalists in Washington that reunification under a free democratic system is the final policy goal of his government.

'As to the issue of the North, the final goal is to reunify (the two Koreas) under a free democratic system,' he was quoted as saying by the independent Hankyoreh daily on November 16.

The CPRF statement came as relations between the two Cold War rivals remain at the lowest ebb since a historic bilateral summit in 2000.

Relations soured after Lee, from the conservative Grand National Party, took office in February, promising to take a firmer line with the North after a decade-long 'sunshine' engagement policy under his liberal predecessors.

The two nations have remained technically at war since their 1950-53 conflict ended without a peace treaty.

The North is also furious at the spreading of propaganda leaflets across the border by Seoul activists. -- AFP