Frenetic negotiations at the UN's climate change summit here may yet produce a deal to reduce greenhouse gas emissions, according to the Minister for the Environment, Mr Dempsey.
Arriving to join the EU ministerial team, he said the US had signalled that it would be prepared to cut a deal, subject to certain conditions which the EU would have to study in detail.
Last night, the broad thrust of the concession now being offered by the US was outlined by Mr Frank Loy, its Under-secretary of State for global affairs, in what the Americans touted as a genuine effort to break the deadlock.
Mr Loy told a press briefing that the US would accept a cap on the use of existing forests and farmland as "carbon sinks", to offset its own greenhouse gas emissions.
Earlier President Jacques Chirac of France appealed to the US to join other leading industrialised countries in making the transition to a more energy-efficient economy.
In an impassioned speech to the conference, he said: "Each American emits three times more greenhouse gases than a Frenchman. It is in the Americans that we place our hopes of effectively limiting greenhouse-gas emissions."
The time had come for action. "We can all imagine the dreadful consequences, ultimately, of inertia and hesitation, such as the disappearance of regulating mechanisms like the Gulf Stream which gives Europe its temperate climate."
Mr Chirac acknowledged the pressure from those with a vested interest in wasting energy to take the "easy route" of relying on loopholes in the 1997 Kyoto Protocol, but said: "We must not allow this to stand in our way."
The French president was echoing the EU's demand that all industrialised countries - including the US, which is responsible for a quarter of global greenhouse-gas emissions - must make real cuts if the treaty is to be credible.
But with the result of the US presidential election still in doubt and the US Congress as well as powerful business interests implacably opposed to such a deal, the American delegation here does not have much room to manoeuvre.
Last night, however, Mr Loy insisted that his team had a mandate from President Clinton to negotiate and reach agreement in The Hague, if possible. He also revealed that he had spoken to Mr Chirac and set him straight on what the US was doing.
But Friends of the Earth and other environmental groups immediately condemned the new US proposal, saying it would still amount to a "giant free gift", possibly amounting to half of the country's Kyoto Protocol obligations.
It also cautioned that even the EU, which has been to the fore in demanding real cuts in emissions, may now agree to a deal which would allow industrialised countries to achieve half of their Kyoto targets by availing of such loopholes.
"What price per tonne of carbon saved are the US and other countries prepared to pay for a deal in The Hague?" it asked. "And what value do they put on the lives, jobs and homes that are being lost as a result of climate change?"
Britain's Deputy Prime Minister, Mr John Prescott, said he expected the summit would have to "go through the pain barrier" of all-night sessions before "emerging into the sunlight" of a credible deal.
He also announced a package of subsidies, worth £30 million sterling over the three years, to encourage British motorists to convert petrol-driven cars to run on gas, or to buy new electric-powered vehicles.
