COPENHAGEN - Environment ministers from 44 key countries on Tuesday wrapped up closed-door talks aimed at laying the groundwork for a political agreement at next month's UN conference on global warming.

Danish Prime Minister Lars Loekke Rasmussen, speaking on the sidelines of the two-day meeting, lauded China and the United States' support for his country's push to reach a politically binding agreement at the conference to take "immediate operational effect."

"I am glad that the Danish strategy was supported today in Beijing at the Chinese-American summit ... it confirms that we have taken the right stance," Rasmussen told reporters.

The talks in Copenhagen brought together representatives from countries at both ends of the climate spectrum, including the planet's two largest emitters of greenhouse gases -- China and the United States -- as well as nations that are among the poorest in the world and most vulnerable to climate change.

The meeting was held in preparation for the December 7-18 UN climate change conference that aims to reach a deal for slashing greenhouse-gas emissions after the Kyoto protocol expires in 2012.

US President Barack Obama said Tuesday China and the US wanted the Copenhagen conference to culminate in a global accord that had "immediate operational effect."

We "agreed to work toward a successful outcome in Copenhagen," Obama told journalists after talks with Chinese President Hu Jintao in Beijing.

Rasmussen said the agreement reached in the Danish capital should be "substantial and concrete, covering all fields," he reiterated, adding it should become legally binding "as soon as possible," without setting a date.

China and the United States together account for 37.5 percent of global emissions of the six main greenhouse gases, according to the World Resources Institute (WRI).

Their positions are key to the outcome of the Copenhagen conference, a two-year process that aims at building a post-2012 planet-wide treaty on tackling climate change.