A US negotiator said the time was not right for negotiations
They were aimed at paving the way for the climate summit taking place in Bali in December which will focus on how to take forward the Kyoto Protocol.
However, the US said it was unlikely to take part in negotiations at the end of this year on a global agreement to cut emissions of carbon dioxide.
The UN acknowledged "sticking points", but said some issues had been resolved at the meeting.
United Nations Framework Convention on Climate Change (UNFCCC) Executive Secretary, Yvo de Boer, said: "We have come closer to broadening negotiations on a post-2012 regime by resolving some of the outstanding issues and clarifying which building blocks of a future agreement need to be put in place."