WASHINGTON » With the clock running out and deep differences unresolved, it now appears there is little chance that international climate change negotiations in Copenhagen in December will produce a comprehensive and binding new treaty on global warming.

The United States and many other major emitting countries have concluded that it is more useful to take incremental but important steps toward a global agreement rather than to try to jam through a treaty that is either too weak to address the problem or too onerous to be ratified and enforced.

Instead, representatives at the Copenhagen meeting are likely to announce a number of interim steps and agree to keep talking next year.

“;There isn't sufficient time to get the whole thing done,”; Yvo De Boer, the Dutch diplomat who heads the U.N. climate secretariat and serves as the de facto overseer of the negotiations, said late last week. “;But I hope it will go well beyond simply a declaration of principles. The form I would like it to take is the groundwork for a ratifiable agreement next year.”;

Negotiators have accepted as all but inevitable that representatives of the 192 nations in the talks will not resolve the outstanding issues in the brief time remaining before the Copenhagen conference opens in December. The gulf between rich and poor nations, and even among the wealthiest nations, is just too wide.

Representatives of the 16 largest emitting countries plus the European Union, who concluded a meeting in London on Monday, said that they had made progress on the level of aid needed to help poor countries adapt to climate change and adopt less-polluting energy technology.

They also said they had settled some questions on the “;architecture”; of any agreement reached in Copenhagen, while acknowledging that it would fall short of a binding treaty.

Yet expectations remain high for a meeting that carries important weight not just for the environment but for a broad range of international issues, including trade, security, economic development, energy production, technology sharing and the very survival of some vulnerable island nations.

So officials are now narrowing expectations and defining the areas where there is agreement, such as the need to halt and then reverse the growth of greenhouse gas emissions, although how and by whom remains the subject of intense dispute. Negotiators are also discussing what form any declaration that emerges from Copenhagen might take and how to ensure that any promises made there are kept.

Among the chief barriers to a comprehensive deal in Copenhagen is Congress' inability to enact climate and energy legislation that sets binding targets on greenhouse gases in the United States. Without such a commitment, other nations are loath to make their own pledges.

The chief American climate negotiator, Todd Stern, has said that he will not go beyond what Congress is willing to endorse. His deputy, Jonathan Pershing, affirmed this last week at a negotiators' meeting in Bangkok. “;We are not going to be part of an agreement we cannot meet,”; he said.

Administration officials and congressional leaders have said that final legislative action on a climate bill will not occur before the first half of next year.

European officials have been pressing hardest for some form of binding treaty modeled on the Kyoto protocol of 1997, which the United States refused to ratify because it imposed emissions limits on developed nations while demanding nothing of rapidly growing economies like China and India.

American officials have said that no agreement at Copenhagen is better than a bad deal that cannot be ratified or enforced. And they note that it took four years after the initial negotiation of the Kyoto accord to complete it.

There is general agreement among international negotiators and knowledgeable observers that the parties to the Copenhagen talks, held under the auspices of the U.N. Framework Convention on Climate Change, will agree to continue discussions next year, and perhaps set a deadline for reaching a final agreement by mid-year or December 2010 at the latest.

The rest of the outcome, even the form it may take, remains uncertain. The world's biggest economies agreed at a meeting last summer in D'Aquila, Italy, on a goal of limiting global temperature increases to 2 degrees Fahrenheit above current levels, though they did not agree on the means to get there or on how to enforce it. Such a goal is expected to be part of any declaration from Copenhagen.

Also likely to be included is a statement that wealthy nations should cut their emissions below certain benchmarks and that emerging economies should reduce their rate of emissions growth below a business-as-usual curve. No numbers were attached to either of these pledges and that remains the stickiest of issues.

Also unresolved is the financial structure of any international climate accord. The wealthy nations have agreed in principle to support low-carbon growth in the developing world and to help those countries hardest hit by climate change to adapt. But the amounts of money, the programs and the countries that would qualify for that support and for cost-sharing among donor nations are highly contentious issues unlikely to be settled at Copenhagen.

There will probably also be a promise to create an international system to monitor, report and verify emissions reductions, although there is no consensus yet on who would perform these tasks and what penalties would be assessed be for failure to comply.

There is also likely to be a commitment by most nations to produce and publish economic growth plans based on lower carbon emissions and an agreement by advanced nations to share clean new energy technology with developing countries.

“;The most likely form any agreement will take will be a political declaration,”; said Nigel Purvis, a former State Department climate negotiator in the Clinton and George W. Bush administrations. “;It could be a statement by senior leaders, or it could be adopted by the parties as a formal decision. That does not make it legally binding, but it sends a signal to the world of the direction the negotiations are going and give guidance to negotiators as they continue their work.”;