The chances of emissions targets being agreed at the UN's climate change conference in Bali were receding fast yesterday, with senior officials expressing concern that the talks were on the brink of collapse.

The EU is reportedly at loggerheads with the US, Japan, Canada and Australia over the roadmap agreement for the next two years of talks to agree a successor to the Kyoto protocol.

European governments remain insistent that the agreement should include a non-binding commitment for developed nations to cut greenhouse gas emissions by between 25 and 40 per cent by 2020 as the guiding principle for future talks.

But the US has rejected the proposal, with US chief negotiator Harlan Watson insisting that including targets at this stage would pre-judge the results of future negotiations. The US has consistently opposed emissions targets, instead advocating a greater investment in clean technology as the best means of tackling climate change.

European delegates yesterday sought to crank up pressure on the US, with Humberto Rosa, Portugal's environment minister, telling a news conference that the EU may now boycott President Bush's planned Washington talks on climate change involving the world's 17 largest economies early next year. "It's true that if we would have a failure in Bali it would be meaningless to have a major economies' meeting," he said.

German officials, meanwhile, were also highly critical of the US position. Quoted in The Guardian newspaper, environment minister Sigmar Gabriel said that the Bali conference would be meaningless if clear emissions targets were not set. "I do not need a paper from Bali in which we only say, 'OK, we'll meet next year again'," he said. "How can we find a roadmap without having a target, without having a goal?"

A Bipartisan group of members of Congress similarly sought to crank up pressure on the Bush White House, issuing an open letter to the UN's top climate change official Yvo De Boer claiming that many in the US supported greater action on climate change.

The letter from Republican Edward J. Markey and 10 House committee chairmen said that "with Congress, the states, cities, and Americans from coast to coast looking to act immediately on global warming, the international community must know they have significant support here in the United States".

However, the US delegation appears unwilling to change its position and has reportedly secured support from Japan, Canada and Australia. "Those who are suggesting that you can magically find agreement on a metric when you are just starting negotiations, that in itself is a blocking element," James Connaughton, chairman of the White House Council on Environmental Quality, told news agency Reuters. "We will lead, we will continue to lead. But leadership also requires others to fall in line and follow."

The stalemate left UN officials concerned that the talks could break down without an agreement, a scenario that would seriously undermine attempts to ensure a successor to Kyoto is in place before it expires in 2012.

"I'm very concerned about the pace of things," said de Boer. "We are in an all-or-nothing situation in that if we don't manage to get the work done on the future [terms for negotiations] then the whole house of cards basically falls to pieces."