The US is willing to sign up to "binding international obligations" on cutting greenhouse gas emissions if other nations do the same, senior White House officials have said.

According to BBC reports, James Connaughton and Daniel Price, environmental and economics advisers to President Bush, revealed the US administration's position at a news conference in Paris yesterday.

"The US is prepared to enter into binding international obligations to reduce greenhouse gases as part of a global agreement in which all major economies similarly undertake binding international obligations," said Mr Price, the president's deputy national security adviser for international economic affairs.

He added that these major economies include "developed and developing [countries] alike".

"Europe and the US could turn out the lights today, and come 2030 or 2050 we would not have addressed the problem of climate change," Price argued, suggesting that large developing economy emitters such as China, India and Brazil would also have to sign up to binding targets.

The targets could take the form of absolute emission cuts or more flexible energy efficiency goals, he said.

The US hopes to deliver some form of agreement between the world's major emitters in the form of a "leaders' declaration" ahead of the July G8 Summit, the BBC reported. However, there was no indication from Connaughton and Price on the scale on the emission targets that might be agreed or the timeline for achieving them.

The latest statements will be welcomed as a significant shift in the US's position after years in which it has refused to countenance binding emission targets. But the likelihood of success at forthcoming UN talks to agree a successor to the Kyoto agreement will rest entirely on the scale of the cuts the US will demand from developing economies as a precondition to its signing up.

Chinese and Indian officials have previously said they will accept emission targets if the US does likewise, but with carbon output per capita far lower in developing economies than in the US they are unlikely to agree to targets that demand significant emission cuts in the near future.

The shift in the US position appears to have come as a result of a series of talks between major emitters proposed by President Bush last year. The initial talks in Washington last autumn were roundly criticised as a publicity stunt with the US reportedly refusing to discuss the topic of binding emission targets. However, delegates at the most recent meeting in Hawaii reported improved relations between the US negotiating team and officials from other countries.

Speaking yesterday, Connaughton said that the talks had made progress and that the US and EU were now working together with the World Trade Organisation (WTO) on plans to slash trade tariffs on clean energy equipment.

"Some countries, in particular the major developing countries, have tariff schedules as high as 70 per cent," he said. "We're trying to get the world to eliminate tariffs, and that could increase global trade in clean energy technologies and services by up to 14 per cent per year."

Meanwhile, in the US experts are predicting that climate change and the environment could climb the agenda in the US presidential race after consumer advocate Ralph Nader launched his fifth bid for the White House. The far-left independent candidate said that a tax on carbon emissions and a ban on nuclear power would form key planks of a campaign that is likely to force the Democratic and Republican candidates to enter a debate on environmental policy.