Ms. Lê Thị Thu Hằng began her diplomatic career in 1996 at the Press and Information Department of the Ministry of Foreign Affairs.

From May 2001 to December 2004, she worked at the Embassy of Vietnam in the Russian Federation, focusing on foreign affairs research and culture–press relations.

In August 2009, she was appointed Deputy Director-General of the Press and Information Department.

From January 2012 to May 2015, she served as Minister Counsellor and Deputy Ambassador at the Embassy of Vietnam in the United Kingdom of Great Britain and Northern Ireland.

From October 2015 to March 2017, she was appointed Acting Director-General, and later Director-General of the Department of Information and Culture under the State Committee for Overseas Vietnamese Affairs.

In April 2017, she became Director-General of the Press and Information Department and Spokesperson of the Ministry of Foreign Affairs.

In August 2021, she was appointed Assistant Minister of Foreign Affairs, concurrently Director-General of the Press and Information Department and Spokesperson of the Ministry of Foreign Affairs.

On December 2, 2022, she was appointed Deputy Minister of Foreign Affairs by the Prime Minister.