Building Confidence

I'm working in Asia and have a student who wants to take the IELTS and study in Canada, he has a fair grasp on grammar and a big vocabulary. When we are chatting his speech is generally fine, but when he starts practicing for the test his speaking becomes very choppy, generally disorganized, and very slow. I think he's lacking in confidence and thinking too much about taking the test. I try to hlep him relax, but it doesn't change much.
I'm wondering what you guys do to help students build confidence and fluency while speaking.