"We will continue to talk to our American partners and remind them of their commitments," European Environment Commissioner Stavros Dimas told reporters.

He said US President George W. Bush agreed at a summit of eight leading industrial nations in July and at a UN summit in September to advance global discussions in Montreal on long-term cooperation to curb climate change.

But Bush's representative at the talks in Montreal, Harlan Watson, has rejected joining any new round of global discussions, saying such talks would inevitably lead to new targets and timetables for emissions curbs that Bush rejects.

"There is absolutely no excuse for any more delay in action," Canadian Prime Minister Paul Martin told a separate news conference.

"To the reluctant countries, including the United States, I say this; there is such a thing as a global conscience and this is the time to listen to it," he said. "Above all, now is the time for action."

The United States is the source of a quarter of all greenhouse gases produced from burning fossil fuels.

'BE BOLD'

French President Jacques Chirac told the ministers to be bold.

"We must now prepare ourselves to go much further," he said in a pre-taped address from Paris, referring to cutting emissions of carbon dioxide, methane and other greenhouse gases widely blamed for global warming.

Delegates to the Nov. 28-Dec. 9 talks have made little progress in agreeing on the shape of the next phase of the UN Kyoto Protocol climate change pact, which caps emissions and has been rejected by Washington and Australia.

Kyoto's first phase, which runs from 2008 to 2012, only covers about 40 wealthy developed nations. Many countries and green groups say the pact will only be effective if all nations, and particularly the biggest polluters, are on board.

But doing so means a huge economic shift for many countries and particularly for rapidly growing developing nations, who say cleaning up could limit growth. Rich nations should be taking the lead, developing nations say.

"This is the most significant economic negotiations the world has embarked on, potentially," said one senior Western government official, who did not want to be identified.

On Tuesday, host Canada circulated a draft proposal that sets out a two-year process for discussing long-term measures to tackle climate change, including promoting greener technology, carbon trading and adaptation.

Some environmentalists say this proposal is a timid step but agreement on it would be positive, given the deadlock.

"I don't think it amounts to very much, but if the United States can sign up to that then it will move the process forward," said Catherine Pearce, climate campaigner for Friends of the Earth.

Most scientists say a build-up of heat-trapping gases from fossil fuels burnt in power plants, factories and cars is warming the Earth and could herald catastrophic changes such as a rise in sea levels spurred by melting icecaps.

About 160 members have ratified the Kyoto Protocol, which binds about 40 industrial nations to cut greenhouse gas emissions by 5.2 percent below 1990 levels by 2008-12. But many of these countries are way above their targets at the moment.

Environmentalists are urging rich nations to forget Washington and instead focus on plans for new cuts beyond 2012, saying the time for dithering was over.