The United States and China clashed on Friday about how to revive climate talks in 2010, complicating the first U.N. session since the acrimonious Copenhagen summit fell short of agreeing a treaty.

Many delegates at the 175-nation talks in Bonn from April 9-11 urged efforts to restore trust between rich and poor countries but few held out hopes for a breakthrough deal to fight global warming at the next major talks in Cancun, Mexico, in late 2010.

In a split between the world’s top two emitters of greenhouse gases, Washington said it wanted talks in 2010 to build on a non-binding Copenhagen Accord for limiting global warming reached by more than 110 nations at the December summit.