Born in Zwolle, Catharine Maria (Nienke) Trooster became the Ambassador of the Kingdom of the Netherlands to Vietnam in 2014. Prior to that, from 2010-2014, she was Deputy Head of Mission and Head of Economic Affairs, Embassy of the Kingdom of the Netherlands in Tokyo, Japan.
She was the Ambassador at Embassy of the Kingdom of the Netherlands in Zagreb, Croatia from 2006 to 2010;
From 2002 to 2006, she was Deputy Head of Mission, Embassy of the Kingdom of the Netherlands in Bucharest, Romania; Senior Policy Advisor Department for North Africa and the Middle East (July 2000 – July 2002); Deputy Head of Mission and Head Development Co-operation at the representative office in Ramallah, Palestinian Territories (Aug 1998 – June 2000); Senior Policy Officer Security Policy Department (Aug 1994 – July 1998); Officer at Multilateral Organizations Department (Aug 1992 – July 1994); Policy Officer at Multilateral Organisations Department.
From 1989 to 1990, Trooster was the third Secretary at the Embassy of the Kingdom of the Netherlands in Budapest, Hungary.
She graduated from University of Groningen in 1988 with major in history.