The presidential office said Thursday it'll address North Korea's expulsion of South Korean officials from the Gaesong Industrial Complex in a principled way.

Expressing regret over the abrupt action, Cheong Wa Dae Spokesman Lee Dong-kwan told a news conference the incident could hinder inter-Korean economic cooperation.

Lee called for a stable system and legal environment for inter-Korean business projects, urging the North to change its perceptions.

He added that Seoul will try to prevent the situation from worsening, while coping with it in accordance with principles.

The spokesman said President Lee Myung-bak also vowed to stick to his principles, while approaching inter-Korean relations in a flexible manner.