President Obama spoke of lofty intentions to help the world reduce greenhouse gases when he addressed delegates to United Nations talks in Copenhagen in 2009.

“We have charted our course, we have made our commitments, and we will do what we say,” he said. “Now I believe that it’s time for the nations and people of the world to come together behind a common purpose.”

But the Obama administration is on track to fall more than $200 million short on its $1 billion pledge to help prevent the cutting and burning of tropical rain forests. Lawmakers have slashed requests on everything from promoting clean energy to helping developing nations cope with the effects of global warming. And although the United States is putting into place standards for autos and trucks that will drastically reduce emissions, its negotiators are fighting with European Union officials over their attempt to regulate U.S. airline carbon emissions.

Any clear indication on where the United States is headed in this arena will have to wait until after the 2012 election, if not later, said Robert N. Stavins, director of the Harvard Environmental Economics Program at the John F. Kennedy School of Government.

“In terms of explicit climate policy, the administration will not be able to deliver, at least between now and 2013,” he said.

The administration responds that it is pressing ahead with regulations to cut emissions from cars and light trucks dramatically by 2025. And greenhouse-gas emissions in the United States have dropped 8 percent between 2005 and 2009, according to the Environmental Protection Agency, although the economic downturn accounts for at least part of the decline.

The United States pledged during U.N. talks to reduce its greenhouse-gas emissions by 17 percent from 2005 levels by 2020.

“We obviously would have liked to get energy and climate legislation done last year, but no one should think this administration isn’t acting,” said Todd Stern, the U.S. special envoy for climate change. “We are acting with landmark provisions on vehicle efficiency and $90 billion of investments to spur efficiency, renewable energy, an electric-car industry, and a smart grid — investments that make us cleaner, more competitive and less carbon-intensive.”

Delivering on international climate assistance has proved more challenging. The administration promised in Copenhagen to provide $1 billion between 2010 and 2012 to prevent tropical deforestation, which accounts for about 15 percent of the world’s annual greenhouse-gas emissions. It also promised to contribute an unspecified share of a broader commitment by rich nations to provide $30 billion in “fast start” financing during that time to the developing world.

What is clear is that the Obama administration has gotten much less than it wants from Congress to fund its climate initiatives. The United States provided $1.7 billion in international climate aid in fiscal 2010, $400 million of which came from U.S. development finance and export credit agencies. It asked for $1.9 billion in fiscal 2011, and administration officials said they were crunching numbers but the total was likely to be lower than 2010’s. The Congressional Research Service puts core climate funds for fiscal 2011 at $946 million, but administration officials predicted other funding would raise the total significantly above that.

House Republicans are seeking even deeper reductions for fiscal 2012. The House Appropriations subcommittee on state, foreign operations and related programs cut all but $70 million for international climate assistance, while the House Foreign Relations Committee eliminated climate funding last month as part of an authorization bill.

“We’re in a tough fiscal environment, but if you look at all forms of U.S. support to promote clean-energy development, prevent deforestation and build resilience against extreme weather — support that helps us as well as other countries — we’re not doing badly,” Stern said.

Nigel Purvis, executive director of the bipartisan commission on climate and tropical forests, estimated that the United States will fall more than $200 million, and maybe as much as $320 million, short of its forestry pledge by the end of this fiscal year unless an independent U.S. foreign aid agency, the Millenium Challenge Corp., approves a massive grant to Indonesia.

“Unlike other parts of the climate issue, forest conservation is supported by liberals and conservatives alike, because saving forests strengthens local communities, reduces societal instability and protects wildlife,” Purvis said. “This is an area of climate policy where the United States can and should do more.”

Last year, the administration funded international projects including a $1.5 million solar energy-powered pump project in Uganda and $3 million to enhance the low-lying Republic of Maldives’ ability to cope with rising sea levels and drinking water access.

But the United States has sought to block the European Union from forcing all foreign carriers as of Jan. 1 to buy pollution allowances for flights to and from Europe if their own countries didn’t regulate carbon emissions.

“Unilaterally including our carriers in an emissions trading system is the wrong way to achieve the right objective,” Krishna R. Urs, the State Department’s deputy assistant secretary for transportation affairs, testified before the House Transportation and Infrastructure Committee .

The U.S. airline industry — including the Air Transport Association, United Continental Holdings and AMR Corp. — is challenging the policy before the European Court of Justice, which heard arguments on it last month.

“If the E.U. is allowed to go forward with this and regulate in our airspace, that would change the face of international aviation,” said Nancy Young, ATA’s vice president for environment.

Isaac Valero-Ladron, E.U. spokesman for Climate Action Commissioner Connie Hedegaard, said in a phone interview that European officials would prefer that the Obama administration “introduce a bill to reduce emissions from aviation, instead of trying to block the only legislation that is trying to address the global problem of aviation emissions.”

Jake Schmidt, international climate policy director for the Natural Resource Defense Council, said the airlines case could undermine America’s negotiating position when it comes to global climate policy. “This is the United States telling another nation not to regulate an emission that the U.S. can’t do anything about.”

But Heritage Foundation policy analyst Nicholas Loris, who opposes a carbon cap as well as an international climate treaty, said the United States would be better off if it was not party to a global warming pact.