Paris, Dec. 11: The UN climate summit spilled over to Saturday as political leaders and negotiators from nearly 200 countries have not yet converged on the final text of an accord despite two weeks of talks.

A fresh draft, released on Thursday, tried to sort out differences of opinion between nations, but seemed stuck on key issues such as finance that developing countries are expecting from developed countries to meet the challenges of climate change. The draft is also not legally binding.

(US President Barack Obama spoke "over an hour" with Prime Minister Narendra Modi on Tuesday over the hotline and discussed the climate talks, ambassador Richard Verma said in Washington.)

Non-government climate policy analysts have criticised the draft for being "inadequate to meet the need of the world".

A senior scientist termed it even "weaker than the Copenhagen" accord, referring to what analysts see as a lame agreement that emerged at a similar UN climate summit in the Danish capital in 2009.

The Paris summit underway at the sprawling Le Bourget conference hall is aimed at getting a global accord to reduce the world's greenhouse gas emissions to prevent the average global temperature rise beyond 2°C.

It is also aimed at establishing mechanisms for the developed countries to route finance and technology to the developed countries to pursue clean energy and adapt to the impacts of climate change.

"It seems that the political leaders more or less have decided what to do to save the world, but still remain undecided on how that can be done," said a representative of Climate Action Network, a global NGO.

"The negotiations are struck because of the lack of flexibility shown by the developed countries towards our key demands," said India's environment minister Prakash Javadekar on the sidelines of the meetings.

Apart from the formal UN meeting, bilateral meetings are also underway to thrash out the differences between parties.

"We have had very good meetings with China and the United States sometimes back and I will soon meet the UN secretary general Ban Ki Moon and the conference president (Laurent) Fabius," Javadekar said.

During the fifth meeting of the Paris Committee on Thursday, that was set up on December 5, Fabius proposed "indaba-type consultations" which he named "indaba of solutions" where he urged countries not to present statements but to provide compromise solutions, possibly referring to important meetings held by Zulu people of South Africa.

He also said that in case of persistent differences, the facilitating ministers would meet separately and report back to the indaba within 30 to 45 minutes. Fabius claimed the new text was prepared to bring "balance, impartiality and reconciled positions," but admitted that differences remained on key issues like finance, differentiation and ambition.

The concept of differentiation recognises differences in the historical and cumulative emissions between developed and developing countries and thus differences in the scale and types of their emissions reduction and curbing actions.

"Compromise does require us to forget the ideal solution for everybody. We are close to the finishing line and we must find common grounds. In other words, the time to come to an agreement," said Fabius.

The new text was reduced from 29 to 27 pages of which 12 pages contained the draft agreement and 15 pages were allocated to the accompanying draft decision.

Experts have criticised the draft for being weak and inadequate to save the world.

"It seemed to have kept all key demands from everybody with smart manoeuvring of languages and that is not the way to save the world" said a civil society representative.

"The draft is regressive as far as equity is concerned. India's stand on differentiation has been diluted in the latest text. There is an effort to shift the responsibility from developed towards developing countries," said Sunita Narain, director general of the non-government Centre for Science and Environment, in La Bourget after analysing the draft.

Climate Action Network and Action Aid have also jointly termed the draft weak especially on issues like differentiation and finance though there have been few positive movements in adaptation.

"Everything is tied to finance and the principle of differentiation; and hence unless these two issues are sorted out, developments in others will not make any substantial impact," said Harjeet Singh of Action Aid.

"The draft has some references to being legally binding but, as of now, large emitters, if they want, have the window to escape," said Sanjay Vasisht of CAN.

Scientists also criticised the draft for not matching what science demands.

"The draft goal of 2°C and pursuing efforts to limit temperature increase to 1.5°C is aspirational. If you look at the options in the current draft text compared to the previous one, options which specifically mentioned 40 to 70 and 70 to 90 percent emissions cuts are out of the current draft. The options consistent with science are replaced by vague formulations," said Steffen Kallbekken, director of the Centre for International Climate and Energy Policy on the sidelines of the talks.

"By the time the pledges come into force in 2020, we will probably have used the entire carbon budget consistent with 1.5°C warming. If we stick with the INDCs we will have warming between 2.7°C and 3.7°C. We need to update them long before 2030" the scientist told The Telegraph.

"Aspiration and rhetoric will not deliver reductions in CO2 emissions; we need to deliver action," said Kevin Anderson, deputy director of the Tyndall Centre for Climate Change Research in the UK.

"This draft agreement is weaker than Copenhagen (and) the current text is not consistent with the latest science. The Copenhagen text covered aviation and shipping emissions, that together are as large as emissions of the UK and Germany combined, but they are not mentioned in the Paris text," Anderson said.