COPENHAGEN (AFP) - Denmark's climate minister will travel to Washington on Thursday to convince the US Senate of the urgency of talks to clinch a deal at the UN climate summit in Copenhagen in December.

"The situation is difficult and serious with less than three months to go before the deadline," Connie Hedegaard told reporters on the eve of her visit, noting that the negotiations were "progressing slowly".

She said Washington's commitment was "vital" to the summit's success.

The US House of Representatives passed a vast climate change bill in late June which calls for a 17 percent reduction of greenhouse gas emissions by 2020 from 2005 levels.

But the Senate has yet to introduce its own version of the legislation.

If, as expected, the Senate passes a different version, the two chambers would have to thrash out a compromise before legislation can go to US President Barack Obama to be signed into law.

Hedegaard said it was important that process be wrapped up quickly, in time for the Copenhagen summit.

"There are a lot of good forces in the Senate who are pushing for this project to succeed," Hedegaard said, adding however that a debate over US health care reform "risked overshadowing the climate priorities".

The December 7-18 talks in Copenhagen, under the 192-nation UN Framework Convention on Climate Change (UNFCCC), aim to craft a post-2012 pact for curbing the heat-trapping gases that drive perilous global warming.

Hedegaard rejected the idea of a compromise accord in Copenhagen if world leaders fail to agree.

"No, we're not even thinking about that. We are aiming for an ambitious agreement, and we will work night and day to achieve that," she told AFP.