(Reuters) – About 175 nations agreed a plan on Sunday to revive climate talks after the fractious Copenhagen summit but the U.N.’s top climate official predicted a full new treaty was out of reach for 2010.

Green Business | COP15

Delegates at the April 9-11 talks, which reopened splits between rich and poor nations from Copenhagen, agreed to hold two extra meetings each at least a week long in the second half of 2010 after the December summit fell short of a binding deal.

The extra sessions, and a linked agreement to prepare new texts about fighting climate change, are meant to help pave the way to the next annual meeting of environment ministers in Cancun, Mexico, November 29-December 10.

And the U.N.’s top climate official, Yvo de Boer, said governments should focus on practical steps in 2010, such as aid to help poor nations cope with the impact of climate change or to promote clean technologies.

“I don’t think Cancun will provide the final outcome,” de Boer told Reuters on the sidelines of April 9-11 talks, the first since Copenhagen and intended to build trust.

“I think that Cancun can agree an operational architecture but turning that into a treaty, if that is the decision, will take more time beyond Mexico,” he said, predicting “many more rounds” of talks to reach an ultimate solution.

Delegates asked the chair of the talks, Margaret Mukahanana-Sangarwe of Zimbabwe, to come up with a new draft text by May 17 about ways to combat global warming to help negotiations on a new treaty in 2010.

It was not decided where and when the extra meetings would be held. The meetings will be in addition to a session in Bonn from May 31-June 11.

“We have made substantial progress in the resuscitation of a positive spirit,” said Dessima Williams, who chairs the Alliance of Small Island States, despite wrangling between rich and poor. “Multilateralism is very slow and complicated.”

“It has been a difficult process,” said Wendel Trio of Greenpeace. “We have agreement on a minimum programme. It’s a start but not an extremely good start.”

The U.N. talks among senior officials were meant to build trust after the December summit merely agreed the non-binding Copenhagen Accord, which has backing from about 120 of 194 U.N. member nations, including all top greenhouse gas emitters.

TWO DEGREES

The Accord aims to limit a rise in average world temperatures to below two degrees Celsius (3.6 F) from pre-industrial times. But it does not spell out how and some poor nations say it is too weak to avert dangerous impacts.

The Accord also pledges $30 billion from 2010-2012 to help developing nations cope with climate change, such as floods, droughts, mudslides and rising seas. Aid is meant to rise to $100 billion a year from 2020.

The United States praised the Accord as a basis for guiding talks in 2010. But many developing nations say that rich nations should do far more to cut their own greenhouse gas emissions.

The head of the European Commission delegation said a cause of gridlock was that neither China nor the United States, the top emitters of greenhouse gases, were willing to take on legal commitments to curb emissions unless the other did.

“That’s where the problem lies in the end,” Artur Runge-Metzger said.