Many questions that were competency based, each question often having three parts. If you know the organization they are easier, but if you don't then you really need to do your research from the TOR on what competencies are necessary.

Applied for an internship as at the New Zealand Permanent Mission to the United Nations. The interview was over the phone and was asked some basic, behavioral and international relations questions by two interviewers. Very simple and quick - lasted less than 30 minutes.