The leader of the ruling Uri Party is set to depart for Tokyo Monday for a four-day visit.

Chairman Lee Bu-young is expected to meet with Prime Minister Junichiro Koizumi, Foreign Minister Nobutaka Machimura and other officials, and discuss pending bilateral issues, including North Korea's nuclear impasse.

The South Korean official said earlier that his visit is part of Seoul's efforts to preserve peace and stability on the Korean Peninsula and prevent a possible deterioration in the standoff over Pyongyang's nuclear ambitions after the November 2nd U.S. presidential election.