New Zealand Trade Minister Tim Groser has warned that the world's expectations for what can realistically be achieved at the Copenhagen climate conference may be too high.
He was speaking at the Royal Institute of International Affairs in London, following the start of negotiations between 190 countries in Copenhagen on a new agreement to deal with climate change beyond 2012.
He warned that any agreements must go further than what was set out under the Kyoto Protocol, with requirements for each country to develop their own policies to counter climate change.
Mr Groser has also promoted the idea of a five-year moratorium to prevent countries from challenging the climate policies of other nations at the World Trade Organisation.
The moratorium would allow some leeway for countries whose policies do not measure up to some others.
Mr Groser is also promoting the benefits of New Zealand's proposal for a global alliance among leading agricultural research institutions, investigating ways to cut agricultural emissions without harming the world food supply.