 China said rich nations must vow greater cuts in greenhouse gas emissions and warned of lost trust in talks over a climate change deal, while rich countries accused Beijing of under cutting progress. Feuding Friday over the future of a key UN treaty on fighting climate change, the Kyoto Protocol, has diluted hopes that negotiations in the Chinese city of Tianjin can lay a firm base for agreeing on a new, binding climate deal next year. The week-long talks end Saturday and are the last before a high-level meeting in Cancun, Mexico, in less than two months. Kyoto's first phase ends in 2012 and what happens after that is in contention, with rich and poor countries disagreeing over whether Kyoto should be extended or replaced with a new treaty that covers all big greenhouse gas polluting nations. In a sometimes combative meeting of hundreds of negotiators, Huang Huikang, China's Special Representative for Climate Change Negotiations, said negotiators were losing trust in each other. "Today here in Tianjin we really need to rebuild trust and confidence. We are losing confidence and trust," Huang said. "We are all concerned about the slow status of our negotiations." The United Nations is worried the talks will stall and create a gap in application from 2013 which could halt Kyoto's $20.6 billion carbon market. TARGETS Beijing wants to keep Kyoto and its firm division between the duties of rich economies and poorer ones, including China. Washington and other rich nations want a new pact to reflect the surge in emissions from the developing world, now accounting for more than half of annual global greenhouse gas pollution. And China wants developed countries to offer far more ambitious carbon cuts before emerging economies also shift. "Now the key issue is the lack of any substantive progress on the developed countries' side. If Annex 1 countries take the lead in the mitigation process, I suppose developing countries will do their part," Huang told reporters. Kyoto binds 37 rich, or Annex 1, nations to meet quantified emissions reduction targets, also called mitigation goals. Under Kyoto, developing countries take voluntary steps to curb the growth of their emissions. The European Union's climate chief, Connie Hedegaard, urged negotiators in Tianjin "to make compromises within the next 24 hours." "We need a substantial package of decisions to be taken in Cancun in order to keep the momentum, to show that international negotiations can deliver," she told reporters in Helsinki. China is the world's biggest greenhouse gas emitter, having passed the United States, but its emissions per-capita remain well below Western levels. China's emissions are set to keep growing for years to come, and it wants rich nations to slash theirs so that it and other developing countries have the room to grow. Huang, the Chinese climate envoy, said the developed nations under Kyoto "must reach the target of more than 40 percent emissions reduction based on the 1990 level (by 2020)." That position is far beyond present targets from the developed world: the US Senate is struggling to approve a vow to cut emissions by about 4 percent below 1990 levels. The wrangling in Tianjin also underscored how vulnerable the tortuous negotiations are to procedural push and shove. Several delegates said China, backed by Brazil, opposed opening up broader discussion of legal issues raised by inserting new numbers into an extended Kyoto after 2012. "China and Brazil are very strongly of the opinion that it makes no sense to start discussing those legal issues as long as there is no clarity about the (emissions target) numbers," said Wendel Trio, a climate change expert with Greenpeace.