Delegates to the U.N. climate change conference are locked in debate over whether to set tough new limits on greenhouse-gas emission, with the United States leading the fight against firm limits. VOA's Nancy-Amelia Collins reports from Indonesia's Bali Island, where delegates are trying to draft a successor to the Kyoto Protocol on climate change.

The U.N. climate change talks being held in Bali hit a snag after the United States said it will not approve a draft agreement setting firm targets for greenhouse gas emissions.

The draft being thrashed out by more than 190 nations at the U.N. conference on the Indonesian island says industrialized country's emissions should be cut by 25 percent to 40 percent by 2020.

The draft negotiating text seeks to set a "roadmap" for future talks on a new global climate change treaty aimed at replacing the Kyoto Protocol, which expires in 2012.

Senior U.S. climate negotiator, Harlan Watson, says Washington firmly rejects mandatory targets.

"Our principle difficulty with having any numbers in the text to begin with [is] it might prejudge outcomes," said Watson. "We are looking for text, I think it is going to be short, to the point, that is going to be balanced, taking into consideration the needs of all parties - and also a text that does not, again, prejudge outcomes that might occur at the end of a two-year negotiating process."

Canada and Japan have also made it clear they oppose Kyoto-like targets. The 1997 Kyoto Protocol, which was rejected by the United States, required 36 industrialized nations to cut greenhouse gas emissions by five percent below 1990 levels by 2012.

The Executive Secretary of the U.N. conference, Yvo de Boer, says firm targets for cuts to greenhouse gas emissions, thought to be a major contributor to global warming, is necessary in order to stop climate change.

"I do think that the scientific community has come with a very clear message," said de Boer. "The scientific community has indicated that really industrialized countries need to reduce their emissions in that order of minus-25, minus-40 by 2020, if we are going to come to grips with this issue."

A final version of the draft must be agreed to by Friday, the final day of the 12-day conference.