<!-- IMAGE -->

United Nations talks on climate change have opened in Bangkok with more than 4,000 participants from 177 countries trying to narrow differences on ways to reduce global greenhouse gas emissions. There are concerns that time is running out on reaching a deal. And, many are looking for concrete steps from the United States.

The U.N. climate change talks opened Monday with warnings that time was running out on reaching a deal.

Industrialized and developing nations have for two years been trying to come up with a workable framework for December negotiations in Copenhagen but with little to show for it.

And with only two months left and numerous hurdles remaining, questions are being raised about whether nations can narrow their differences in time.

Yvo de Boer, the U.N.'s top climate change official, told delegates there was still time to break deadlocks, but he said countries that could be more ambitious should act now.

"The political winds are behind you, the negotiating sails are set," he said. "With all my heart, I urge you to pull up an anchor and make full sail before we lose the tide and are left stranded on the beach, exposed to the coming storms."

Many nations have pledged to reduce greenhouse gas emissions, but are falling short of the target reduction of 25 to 40 percent of 1990 levels.

The European Union has the most ambitious target of 30 percent reduction, while Japan recently announced a 25 percent reduction target.

De Boer told journalists that nations were waiting to see what position the United States would take in the talks.

John Pershing, Washington's deputy special envoy for climate change, says President Obama supports U.S. emission reductions comparable to the European Union and Japan, but wants legally binding commitments from other countries as well.

"We're looking at a process where we can take national commitments and have those enforced," said Pershing. "And, at the international level have a process thorough which countries stand behind the actions they inscribe."

Greenhouse gas emissions such as carbon dioxide are thought to be a major cause behind rising temperatures that have lead to extreme weather and food shortages.

The two weeks of talks in Bangkok will be followed by November talks in Barcelona before the final negotiations.