Switzerland is one of 46 countries to have given its support on Saturday to France's bid to create a more powerful United Nations environmental agency.
But a top Swiss official said that the process was likely to be a lengthy one and that several countries – both developed and developing – were against the move.
The Paris appeal, which follows a major climate conference being held in the French capital, calls for the creation of a tougher UN Environmental Organisation (UNEO).
The existing UN Environment Programme (UNEP), based in Nairobi, has often been criticised for having too limited powers.
French President Jacques Chirac launched the appeal the day after the release of a landmark environmental report from the world's leading climate scientists and government officials, which warned that global warming was so severe that it would continue for centuries and that humans were to blame.
The Intergovernmental Panel on Climate Change's report sparked worldwide calls for action, but not every country has welcomed the idea of a UN body that would define and possibly enforce environmental rules.
The United States, China, India and Russia are among those who have not signed up.
Switzerland has given its support, but an official has warned that the process would take some time. "There is still a lot of work to do to convince [countries]," Thomas Kolly, head of the international division at the Federal Environment Office, told the Swiss news agency.
Kolly, who has been accompanying Environment Minister Moritz Leuenberger to the Paris conference, said the new agency had to be a global organisation with all the partners on board.
Most European countries, and some developing countries, including many from Africa, are in favour of the plan.
Speaking on Friday, Leuenberger said that the organisation would reinforce the international environmental system and increase its visibility.
But Kolly said that emerging countries such as China and India still had their doubts. " [They] are still very negative. They are afraid that they will be subject to a more binding regime than present," Kolly was quoted as saying.
If the body gets the go-ahead, its headquarters will be in Nairobi - a move welcomed by Kolly, who said that currently the UNEP is the only UN agency based in Africa.
The new organisation would be based on the UNEP and would strengthen it, added Kolly.
The much-awaited environmental report has caused concern in Switzerland. Leuenberger called it alarming, especially as Switzerland is an alpine country and particularly affected by climate change.
On Friday and Saturday the main Swiss political parties – with the exception of the rightwing Swiss People's Party – stepped up their demands for immediate action on the environment.
And on Sunday, the newspaper SonntagsBlick reported that the majority of Swiss were afraid of climate change and that they thought people were to blame for global warming.
In all, 63 per cent said that climate change was a serious threat to mankind, according to a survey carried out by the Zurich-based tabloid.
Most wanted more action by the government and 88 per cent of those asked said they were ready to contribute to reducing CO2 through measures such as using the car less and paying more for alternative energy.
However, a majority said they were against the building of any more nuclear power plants in the country.
swissinfo with agencies
In the latest IPCC report scientists said it was "very likely" - or more than 90% probable - that global warming was man-made.
The report predicts a "best estimate" that temperatures would rise by between 1.8-4°C in the 21st century, within a likely range from 1.1-6.4°C.
The study projects a rise in sea levels of between 28-43cm in the 21st century - and said bigger gains could not be ruled out if ice sheets in Antarctica and Greenland thaw.
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