His first overseas posting was to New Delhi. After that, he worked in the United Nations Division at the foreign ministry's headquarters. At the time of Park Chung Hee's assassination, Ban was First Secretary at South Korea's Permanent Observer Mission to the UN in New York City (South Korea only became a full UN member state on September 17, 1991). He subsequently assumed the post of Director of the United Nations Division. He has been posted twice to the Republic of Korea (ROK) Embassy in Washington, D.C. Between these two assignments he served as Director-General for American Affairs in 1990 – 1992. He was promoted to the position of Deputy Minister for Policy Planning and International Organizations in 1995. He was then appointed National Security Advisor to the President in 1996, and assumed the office of Vice Minister in 2000. His most recent post was as Foreign Policy Advisor to the President Roh Moo-hyun.