South Korea today urged North Korea to end its military provocations. However, Pyongyang threatened Seoul with the severest punishment over the massive joint war games planned with the United States. Both exchanged tit-for-tat warnings as the South unveiled a roadmap for the reunification of the Korean peninsula on the eve of the 10-day exercise involving some 56,000 South Korean and 30,000 American soldiers. In a speech to celebrate Korea's liberation from Japanese colonial rule in 1945, South Korea's President Lee Myung-Bak said the Koreas need to overcome the current state of division and proceed with the goal of peaceful reunification. Lee warned that South Korea would not tolerate any military provocations from its neighbour. However, Pyongyang issued a fresh warning today that its army and people would deal a merciless counterblow to the United States and South Korea over the war games as it had already resolved and declared at home and abroad.