The United States and the European Union said Tuesday that they would promote an "ambitious and comprehensive" agreement on climate change at the Copenhagen conference, and strengthen efforts to develop strong carbon-markets.

"Together, we will work towards an agreement that will set the world on a path of low-carbon growth and development, aspires to a global goal of a 50 percent reduction of global emissions by 2050,and reflects the respective mid-term mitigation efforts of all major economies, both developed and emerging," said a common declaration issued after the 2009 U.S.-EU Summit, which was held in Washington.

Climate change topped the agenda at the summit, which was attended by U.S. President Barack Obama, European Commission President Jose Manuel Barroso, EU foreign policy chief Javier Solana, and Swedish Prime Minister Fredrik Reinfeldt, whose country is holding the half-year EU rotating presidency since July.

"We recognize the scientific view that the increase in average global temperature ought not to exceed 2 degrees Celsius above pre-industrial levels. We are prepared to work to mobilize substantial financial resources to support adaptation for the most vulnerable and to support enhanced mitigation actions of developing countries," said the declaration.

The top two economies also vowed to strengthen efforts to develop "strong and well-functioning" carbon markets, which they said "are essential to maximize climate finance and to engage emerging and developing countries in ambitious emissions reduction actions."

As one of the substantial outcomes of the summit, the United States and the EU announced the creation of a ministerial-level U.S.-EU Energy Council, which will "improve energy security and contribute to achieving our ambitious climate change goals."

The White House meeting, the first formal summit between Brussels and Washington for the Obama administration, was held just 33 days ahead of the UN Climate Change Conference in Copenhagen, Denmark.

The EU member states have agreed on issues related to climate change, such as "climate financing," technology transfer, adaptation, mitigation and good governance, forming a unified stand for negotiation at the Copenhagen conference.

The Obama administration, which has publicized an ambitious 80-percent greenhouse gas reduction below 1990 levels by 2050, joined other major developed countries at the G8 summit this July in Italy's L'Aquila to support a goal of keeping the world's average temperature from rising more than two degrees Celsius.

The U.S. House of Representatives has historically passed a climate change bill, which would cut carbon emissions by 17 percent from 2005 levels by 2020 and 83 percent from 1990 levels by 2050. The bill, however, has to be passed by the Senate before becoming a law.