The international community starts a meeting for the U.N. Framework Convention on Climate Change next week in Cancun.
World leaders are calling for a balanced set of decisions to find a common environmental agreement at the climate summit.
Robert Orr, U.N. assistant secretary-general for policy planning, said he didn't think all of the issues related to global climate change would be solved at the conference.
"Significant progress is possible in Cancun," he said in a statement. "That is not to say that we expect all issues to be resolved."
He said U.N. Secretary-General Ban Ki-moon would call for consensus-building on forestry, technology transfer and long-term financing to help governments tackle climate change issues.
Global climate negotiations remain deadlocked after the Copenhagen climate summit last year ended without a binding climate protection agreement.
Orr said that despite political wrangling, he had modest hope for the climate summit that runs through Dec. 10.
"There are enough issues that are close to resolution that give us hope that an important outcome could be achieved in Cancun," he said.