At the conclusion of the US-EU 2009 Summit, both sides also agreed to achieve the goal of a world free of nuclear weapons and fight protectionism.

The US and EU, which account for over half of world's GDP, in a joint declaration agreed to promote an ambitious and comprehensive international climate change agreement at the upcoming Copenhagen Climate Change Summit.

"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% reduction of global emissions by 2050, and reflects the respective mid-term mitigation efforts of all major economies, both developed and emerging," it said.

Following up on the G-20's declaration at Pittsburgh, the joint declaration said: "We commit to remain vigilant to take actions to assure a strong recovery and to plan for cooperative and coordinated exit strategies to be implemented once recovery is ensured."

The US and EU are committed to undertake financial regulatory reforms to improve the resilience of the financial system to prevent future crises, create a 21st century global economic architecture, and address pressing global challenges including energy security and climate.

The statement said: "We will lead by example by respecting our G-20 commitments to refrain from raising or imposing new barriers to trade and investment. We are committed to supporting efforts by the WTO and other international institutions to monitor new trade barriers with a view to increasing transparency in global trade."

Expressing support for the entry into force of the Comprehensive Test Ban Treaty, the declaration called for the start of negotiations on the Fissile Material Cut-Off Treaty in January 2010.

The statement reiterated the necessity for Iran and North Korea to fulfill their international nuclear obligations.

Welcoming the conclusion of electoral process in Afghanistan, the declaration urged new government to swiftly develop an agenda focused on the serious challenges facing the country.

Earlier at the end of the meeting, Obama said they discussed their shared commitment to success in Afghanistan and Pakistan, where EU civilian assistance has played an absolutely critical role.

"We discussed climate change extensively. And all of us agreed that it was imperative for us to redouble our efforts in the weeks between now and the Copenhagen meeting, to assure that we create a framework for progress in dealing with what is a potential ecologic disaster," he said.

The US President said the leaders discussed the situation in Iran, and emphasised how important it is for the US and the EU to coordinate carefully and closely in sending a clear message to Tehran.

"...we want them to be a full member of the community of nations, but that they have to act consistent with international rules and responsibilities with respect to their nuclear program," Obama said.

"We reaffirmed our commitment to strong, sustained economic growth that was articulated by the G-20 in Pittsburgh, and reaffirmed our intent to continue to expand trade and resist protectionist measures between the United States and the European Union.

"We spoke about how we can actually coordinate more effectively in preventing terrorism from spreading between our various countries," he said.

European Union Commission president Jose Manuel Barroso said in this age of globalisation, it is quite obvious that the US and Europe can make a real difference.

"We are working for a framework agreement in Copenhagen that will be an important agreement for the world. We had a particularly very good discussion on this today.

And I think that was one of the most important points of our exchange," he said.