Sustainable has two meanings. First, it's sustainable in the sense that it's going to be self-sustaining in terms of being private sector led and inclusive in terms of making sure that the economy isn't just being fuelled by assistance dollars but that it is going to be self-generating. Secondly, it means sustainable in terms of its impact on the environment, ensuring that it is environmentally sustainable, making sure that it is part of a sustainable environmental framework for the country in question. So it would have both an economic and an environment aspect to it.
On May 25th, 2010. See this statement in context.