BONN, August (Reuters) - UN climate talks have moved backward rather than forward towards a hoped-for deal later this year as nations make slow progress on pledges to cut greenhouse gas emissions and add more proposals to the working document. As talks in Bonn on a new climate treaty drew to an end on Friday, the frustration of delegates with the process this week was clearly felt, and a deal in Mexico this year looks increasingly out of reach. This week's meeting is the penultimate before a meeting set for the end of November in Cancun, Mexico. "I came to Bonn hopeful of a deal in Cancun, but at this point I am very concerned as I have seen some countries walking back from progress made in Copenhagen," said Jonathan Pershing, the U.S. deputy special climate envoy. A new climate text under discussion on the last day of talks in Bonn has increased to 34 pages from 17, though at its peak last year it totalled 200 pages. The text is intended as a blueprint to guide negotiators in overcoming rifts between rich and poor nations when they meet again at the next session in October in China. The pace of negotiations has slowed as some countries have gone back on issues agreed in the Copenhagen Accord last year and as proposals have been added to the text or reinserted. At the time of writing, proposals for the deepest cuts in emissions of at least 95 percent below 1990 levels by 2050 have been reinserted alongside other options, after being taken out of an earlier draft. "The text is larger than it needs to be for us to reach an agreement (in Cancun)," Pershing said. SLOW PACE "We are still having to entertain new inputs into the text," added Dessima Williams, chair of the Alliance of Small Island States. In discussions behind closed doors, Williams said she had not seen any clarifications from rich nations on their emissions cut pledges. "We cannot anticipate any major shift from what we had in Copenhagen, which was a 12 to 18 percent reduction when the IPCC called for 25 percent. We are far from that in the aggregate figures," she said. But Pershing said discussions focussed too much on putting the onus on only rich nations to deliver cuts, rather than all countries. Climate finance is also an area of disagreement. The Copenhagen Accord last December set a long-term goal of raising $100 billion (£63 billion) a year by 2020 to avert the effects of climate change. It also fixed a short-term goal of $10 billion a year by 2012 to aid developing nations. Pershing said some countries were seeking "staggering sums out of line with reality." Another setback to the talks arose from the lack of legislation to curb emissions in the United States. The US Senate dropped efforts to put emissions curbs in an energy bill that is now focussed narrowly on reforming offshore drilling, but the country has said it will stick by its 2020 target for reducing emissions. "It has been taken as a signal by some that the process should be slowed or we should wait for the US," Williams said.