South Korean President Lee Myung-bak said on Wednesday the nuclear crisis on the peninsula must be tackled by negotiation. Lee also called for fresh dialogue between the two Koreas. Six-party talks aimed at dismantling North Korea's nuclear work, which the North walked out of two years ago, were the only available forum to end the North's nuclear programme in return for economic aid and diplomatic recognition, Lee said at a policy briefing by the Foreign Ministry. "I think removal of the North Korea nuclear programmes should be achieved through six-party talks next year," he was quoted as saying by Reuters.