The International Energy Agency in a review of New Zealand's energy policies found a "demonstrated and visible" commitment to energy reform.
The country in 2008 used renewable energy to generate 64 percent of its energy. That figure jumped to 73 percent in 2009, one of the highest increases for members of the Organization for Economic Co-operation and Development.
IEA Executive Director Nobuo Tanaka said that, while New Zealand deserved praise of its sound energy policies, its energy strategy could be strengthened.
"Over the long term, New Zealand must continue to enhance its policies in order to ensure a secure, sustainable and decarbonized future," he added.
He said Wellington set a 2025 target for generating 90 percent of its energy from renewable resources. Draft proposals from the New Zealand government, however, showed a lack of commitment, the IEA said.
"The government needs to assign priorities for working toward goals it can realistically achieve in order to demonstrate early effectiveness and lead to confidence building," the IEA report read. "The strategy is missing a firm set of actions to achieve its stated goals."