New Zealand can't commit to specific emission cuts until rules around forestry are worked out, Climate Change Minister Nick Smith said at United Nations global climate talks in Cancun, Mexico.
New Zealand was committed to playing a constructive role to secure a legally binding and comprehensive agreement, he said.
Forestry was a key issue for New Zealand.
"We therefore welcome the progress being made towards workable accounting rules that have environmental integrity," he said.
"New Zealand's emissions are so sensitive to variations in forestry rules that we cannot commit to a specific future target until they are clear."
The Government wants rules to allow forests planted pre-1990 to be harvested and re-planted in other parts of the country. It also wants to be able to lock up emissions where wood is harvested but used in the production of furniture rather than have it count as being consumed and its emissions released on felling.
Dr Smith said New Zealand also wanted an open debate on fossil fuel subsidies.
"It is ironic that while we try and design pricing instruments to recognise the environmental cost of emissions, the world spends hundreds of billions of dollars a year subsidising fossil fuels and pollution.
"If we are serious about addressing climate change in the most efficient way, we need to be discussing a phase out of such support."
New Zealand as a small developed country was determined to do its share, he said. It had set up an emissions trading scheme, was helping Pacific neighbours deal with climate change and initiated the global alliance -- an international grouping to research reducing emissions from agriculture.
The talks, which require unanimity to progress, are seeking a successor for the UN's 1997 Kyoto Protocol, which obliges almost 40 developed nations to cut greenhouse gas emissions by at least 5.2 percent below 1990 levels by 2008-2012.
The United States never joined Kyoto, believing it would cost US jobs and excluded developing nations. Last year's talks in Copenhagen did not make significant progress and the deadlock between rich and poor countries continues. Developed countries insisted emerging economies also commit to emissions cuts, while those countries, led by China, insist the developed world must first deliver results.