Washington, Dec 11 - Three key US senators has said they had the outlines of a compromise on far-reaching climate legislation that has been stalled for weeks in the Senate.

Senators John Kerry, a Democrat, Joe Lieberman, an Independent, and Lindsey Graham, a Republican, released a four-page "framework" that they said would help wean the US off its dependence on foreign energy sources and protect the economy.

The compromise endorsed President Barack Obama's target of cutting US greenhouse-gas emissions 17 percent below 2005-levels by 2020. It gives the president some added momentum ahead of his travel to the Copenhagen climate change summit next week.

"The framework we are releasing today is a starting point for our negotiations going forward," Kerry said Thursday. Governments meeting in Copenhagen should take the message that "the United States Senate is committed to addressing this challenge".

White House spokesman Robert Gibbs welcomed the compromise as a "positive development towards reaching a strong, unified and bipartisan agreement in the US Senate".

The House of Representatives approved similar legislation in the spring, but it has struggled to make headway over the past few months in the Senate. (dpa)