[1] Ahn joined the South Korean Ministry of Foreign Affairs in 1979 after graduating with a political science bachelor's degree from Seoul National University in 1978.

[2] His first overseas posting was at the South Korean embassy in New Delhi, India.

[3] In March 2011, he became South Korean ambassador to Belgium and the European Union and then First Vice Foreign Minister, the South Korean Foreign Ministry's number-two position, in February 2012.

[4][5] During a February 2018 visit by U.S. Vice President Mike Pence, the Vice President's aides mistakenly told reporters Ahn would greet the Vice President in his capacity as South Korean ambassador the United States The greeter was Cho Yoon-je, who had succeeded Ahn as ambassador, forcing a correction from the Vice President's office.

[6] From 2018, he is working as President of University of North Korean Studies.