President Barack Obama: "We know this progress alone is not enough"
Key states have reached what they call a "meaningful agreement" at the Copenhagen climate summit.
Five nations, including China and the US, reached a deal on a number of issues, such as a recognition to limit temperature rises to less than 2C.
US President Barack Obama said it would be a foundation for global action but there was "much further to go".
However, the deal could be rejected as a number of nations expressed "dissatisfaction" with the contents.
"Can I suggest that in biblical terms, it looks like we're being offered 30 pieces of silver to sell our future," Tuvalu's lead negotiator Ian Fry said during the main meeting. "Our future is not for sale."
AT THE SCENE
Richard Black, BBC News environment correspondent
President Obama may have a deal with Brazil, China, India and South Africa - but it is not at all clear that he has a deal with anyone else.
While the White House was announcing the agreement, most other delegations had not even seen it.
This has clearly annoyed a number of countries who, when the agreement document, expressed their distaste in vigorous language - a "coup d'Etat against the UN".
With no firm target for limiting the global temperature rise, no commitment to a legal treaty and no target year for peaking emissions, countries vulnerable to climate impacts are pointing out this "deal" does not guarantee the temperature targets they need.
Mr Fry said his country could not accept the deal, as did Venezuelan delegate Claudia Salerno Caldera.
"Mr President, I ask whether - under the eye of the UN secretary general - you are going to endorse this coup d'etat against the authority of the United Nations."
Nicaragua submitted new documents to the meeting calling for the resumption of negotiations on new legal agreements, including emission reductions from developed nations.
To be accepted as an official UN agreement, the deal needs to be endorsed by all 193 nations at the talks.
The five-nation deal promised to deliver $30bn (£18.5bn) of aid for developing nations over the next three years, and outlined a goal of providing $100bn a year by 2020 to help poor countries cope with the impacts of climate change.
President Obama said the US, China, Brazil, India and South Africa had "agreed to set a mitigation target to limit warming to no more than 2C and, importantly, to take action to meet this objective".
He added: "We are confident that we are moving in the direction of a significant accord."
US-LED COPENHAGEN DEAL
No reference to legally binding agreement
Recognises the need to limit global temperatures rising no more than 2C above pre-industrial levels
Developed countries to "set a goal of mobilising jointly $100bn a year by 2020 to address the needs of developing
On transparency: Emerging nations monitor own efforts and report to UN every two years. Some international checks
No detailed framework on carbon markets - "various approaches" will be pursued
"The meeting has had a positive result, everyone should be happy," said Xie Zhenhua, the head of China's delegation.
"After negotiations, both sides have managed to preserve their bottom line. For the Chinese, this was our sovereignty and our national interest."
The agreement also included a method for verifying industrialised nations' reduction of emissions. The US had insisted that China dropped its resistance to this measure.
During the two-week gathering, small island nations and vulnerable coastal countries have been calling for a binding agreement that would limit emissions to a level that would prevent temperatures rising more than 1.5C above pre-industrial levels.
The G77-China delegation forced a number of suspensions in negotiations, accusing the Danish hosts of chairing the conference in a "undemocratic fashion", saying its views were being overlooked.
EU Commission President Jose Manuel Barroso told reporters: "I will not hide my disappointment regarding the non-binding nature of the agreement here.
It is now evident that beating global warming will require a radically different model of politics than the one in Copenhagen
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