NUSA DUA, Indonesia, Dec. 15 -- The United States, under a barrage of criticism from developing countries, agreed today to accept a framework for future climate change talks that would compel industrialized countries to provide measurable technological and financial aid to lesser-off nations if they take verifiable steps to reduce their greenhouse gas emissions.

The compromise, forged mid-day Saturday after a series of around-the-clock negotiations involving 187 nations, bridged the differences between Bush administration officials' insistence that rapidly industrializing nations do their part to address global warming and the developing world's call for greater climate action by Washington.

Under the deal, which will provide the framework for negotiating a new global warming treaty over the next two years, developed nations must take binding "commitments or actions" to cut their emissions, and poorer nations must also seek to reduce their contributions to human-induced climate change.

"This is a real breakthrough, a real opportunity for the international community to successfully fight climate change," said Indonesian Environment Minister and President of the conference, Rachmat Witoelar. "Parties have recognized the urgency of action on climate change and have now provided the political response to what scientists have been telling us is needed."

But the agreement only came together after the talks nearly collapsed Saturday afternoon when Undersecretary of State for Democracy and Global Affairs Paula Dobriansky told the delegates that the United States was "not willing to accept" language calling on industrialized nations to produce "measurable, reportable and verifiable" assistance to developing countries.

Those comments sparked a round of boos and hisses from the audience -- a rare event in the context of a U.N. negotiation -- and a sharp rebuke from an array of developing countries.

Marthinus van Schalkwyk, South Africa's minister of environmental affairs and tourism, called Dobriansky's comments "unwelcome" and questioned why the United States was not doing more to address global warming when leaders from emerging economies had agreed to taking measurable and verifiable steps to reduce their emissions.

"It has never happened before," van Schalkwyk said of his and other developing countries' willingness to be judged on their climate efforts. "A year ago it would have been unthinkable."

In rapid succession, other developing nations also chastised the U.S. for blocking a global agreement.

"If you cannot lead, leave it to the rest of us. Get out of the way," said Kevin Conrad, Papua New Guinea's ambassador for climate change.

Alden Meyer, director of strategy and policy for the Union of Concerned Scientists, said the standoff between American and other nations helped inspire the developing world to "pull together to keep the process alive before it sunk.

"I've been in this business for twenty years, and I've never seen a drama like that in the U.N. process," he added.

Afterward, administration officials said today they were pleased with the outcome. They had succeeded in one goal, eliminating language calling on industrialized countries to cut their emissions 25 to 40 percent by 2020 -- a high priority for the European Union -- and said they now have major emitters such as Brazil, China and South Africa willing to engage more aggressively in the push to reduce global warming pollution.

"We needed to establish here in Bali, through the negotiations, that we're launching a shared commitment to cutting greenhouse gases," James L. Connaughton, chairman of the White House Council on Environmental Quality, told reporters. "We now have one of the broadest negotiating agendas on the question of climate change."

European leaders said that while they had hoped for a stronger document to steer the climate talks that will culminate in Copenhagen in late 2009, they view the Bali road map as a critical step in forging a new global warming pact. That future agreement will determine how deeply industrialized countries cut their emissions between 2012 and 2016, after commitments made under the 1997 Kyoto Protocol expire. The United States never accepted that pact.

The European Parliament issued a statement praising EU delegates for "having secured the best politically viable outcome here at Bali."

And while German environment minister Sigmar Gabriel suggested earlier in the week he and others might boycott future meetings of the parallel climate talks President Bush launched in September, his spokesman Michael Schroeren said today that Germany will continue to participate in the White House negotiating sessions.

"We are very interested in making the Major Economies Meeting a success," Schroeren said, referring to Bush's climate talks. He added that by demonstrating flexibility during today's negotiations, the U.S. delegation "has contributed to the success of the meeting. It has made a great contribution."

Connie Hedegaard, Denmark's climate and energy minister, said the most important thing about today's consensus document is "the doors are not shut" to a future climate pact calling for deep emissions reductions. But she added, "The whole document shows how many stones there are still on this road that need to be removed . . . There is still no guarantee we will succeed in getting a new global agreement in 2009."

David Doniger, climate policy director for the advocacy group Natural Resources Defense Council, called the Bali consensus statement "the start of the world's last chance to pull off a treaty to stave off the worst effects of global warming."

The agreement also seeks to help poorer nations reduce their emissions by easing the transfer of clean energy technology and would bolster their ability to adapt to such climate change impacts as flooding, drought and the spread of disease. The agreement calls for any future climate pact to seek out "new and additional resources" for poor countries struggling to adapt to global warming.

Officials said another aspect of the package, which aims to compensate poor nations in Africa, Asia and Latin America for protecting their rainforests, would ensure that the future climate agreement to be negotiated by 2009 will reduce greenhouse gas emissions that arise from the burning and logging of forests worldwide.

"This really is a watershed moment," said Andrew W. Mitchell, executive director of the Global Canopy Program, a British-based consortium of scientific institutions and conservation groups.

Ned Helme, president of the D.C.-based Center for Clean Air Policy, said Norway's recent commitment to allocate $500 million a year toward protecting forests helped ease developing countries' concern that these projects would be used as "carbon credits" by industrialized nations hoping to avoid cutting their own emissions.

"That's real money," Helme said of Norway's commitment. "To me, it makes it possible to solve this."

Even as politicians and environmental activists welcomed today's agreement, however, they acknowledged it marked just the beginning of an even more difficult negotiating process.

"My team worked so hard to prepare for this, and we suddenly realize that we're going to be working even harder for the next two years," said Hans Verolme, who directs the World Wildlife Fund's climate change program. "This is the beginning of a journey."