The US and EU have reached provisional agreement on curbing greenhouse gas emissions at UN climate talks in Bali.
The US says it will accept a compromise text on curbing global warming thrashed out at UN climate talks in Bali.
They have agreed on a document launching negotiations on future emissions cuts, but - as demanded by the US - it lacks firm targets.
The compromise deal softens the commitments placed on developing countries to restrain their greenhouse gas emissions in the future.
But major developing nations including China and India have raised objections to some key sections of text.
The US accepted the deal minutes after signalling its rejection, which had brought rounds of boos from delegates.
They want richer countries to make more concrete pledges on transferring clean technology to the developing world.
Earlier, the EU and US agreed that industrialised countries would not set firm emissions targets at this stage.
"They don't want to give us technology support," said India's Science Minister Kapil Sibal.
"(The text) says 'support for technology' - what does 'support' mean? Support from where?"
Your work is not yet over...everybody should be able to make compromises Ban Ki-MoonUN Secretary General Q and A: Bali summit
Some developing country delegates complained they had been put under "strong pressure" to curb their emissions, according to Munir Akram, UN ambassador for Pakistan who chairs the G-77 bloc of nations.
Mr Munir hinted that "threats" had come in the form of trade sanctions.
And Chinese delegates were angry that a plenary session had been called while they were still involved in closed-door talks.
An un-named Chinese delegate called a version of the draft text drawn up by the summit hosts Indonesia as a "conspiracy".
Objections by these major developing nations raised new doubts over whether the summit will achieve consensus, with talks continuing more than a day after their scheduled close.
'Ambiguous' elements
The earlier major disagreement, which had seen the EU deadlocked with a bloc containing the US, Canada and Japan, was resolved with a text that did not mention the specific emissions targets demanded by Europe but which did acknowledge that industrialised nations would have to make major cuts.
EU negotiators had wanted a commitment that industrialised nations would cut their emissions by 25-40% compared to 1990 levels by 2020.
Instead, the draft recognises that "deep cuts in global emissions will be required to achieve the ultimate objective", and sets a finish date for negotiations of 2009.
The date is designed to allow governments and businesses to adjust to any new targets before they enter into force in 2012, when existing targets in the Kyoto Protocol expire.
UN Secretary General Ban Ki-moon - who flew back to Bali on an unscheduled detour - said that the fact a 2009 deadline had been agreed was "encouraging".
But he added: "Your work is not yet over...everybody should be able to make compromises."
On the issue causing most concern to the US - the issue of mandatory emissions cuts - the text is highly ambiguous, comments BBC environment correspondent Matt McGrath who is at the Bali summit.
It requires developed nations to support "nationally appropriate commitments or actions" - a favoured US expression.
But it says this may include "quantified emissions limitations objectives" - in other words, mandatory cuts.
The nature of this text could allow a new US administration to sign up for legally binding limits at the end of this process in 2009.
Our correspondent says there is no mention of any need for emissions globally to peak and begin to fall within 10-15 years or for them to be halved by 2050.
Both were key messages emerging from the Intergovernmental Panel on Climate Change's (IPCC) landmark assessment of climate science, impacts and economics, published over the course of 2007.
Target missed
Environmental groups and some delegates have criticised the draft as being weak and a missed opportunity.
If this does its job, deforestation goes down to nothing Andrew Mitchell, Global Canopy Programme Send us your comments
France's Deputy Ecology Minister Nathalie Kosciusko-Morizet acknowledged the deal amounted to far less than the EU had wanted.
But, she told the AFP news agency: "The public can understand that we brought the United States into the negotiations.
"It's a framework that is quite weak but which still moves forward."
US Deputy Assistant Secretary of State, Kurt Volker, defended the reluctance to agree to specific emissions reductions targets.
"It's one thing to put out a number, it's another to have the policies in place" to enable all countries to plan beyond the 2012 Kyoto targets, he told the BBC's Newsnight programme.
Tree line
Provisional agreement was reached on several other issues, including paying poorer countries to protect their forests.
Delegates have continued into an extra day of discussions
This is widely acknowledged as the cheapest single way of curbing climate change, and brings benefits in other environmental areas such as biodiversity and fresh water conservation.
Delegates agreed on a framework that could allow richer nations and companies to earn "carbon credits" by paying for forest protection in developing countries.
"We need to find a new mechanism that values standing forests," said Andrew Mitchell, executive director of the Global Canopy Programme, an alliance of research institutions.
"Ultimately, if this does its job, [deforestation] goes down to nothing."
Mr Mitchell said the only feasible source of sufficient funds was a global carbon market.
But many economists believe mandatory emissions targets are needed to create a meaningful global market.
