In a speech to mark the 80th anniversary of Korea's liberation from Japanese colonial rule, Lee said he would restore the so-called September 19 Comprehensive Military Agreement, a de-escalation measure that halted some military activities at the border between North Korea and South Korea.

South Korean President Lee Jae Myung pledged to "respect" North Korea's political system and said Seoul would not seek unilateral reunification in a speech to mark Liberation Day.

South Korean President Lee Jae Myung, who has been seeking to improve strained relations with Pyongyang, ordered on Monday his cabinet to prepare a partial step-by-step implementation of existing agreements with North Korea.