Chicago: President Barack Obama said that the transition in Afghanistan to wind down the war was "well underway", but insisted on a long-term relationship with Kabul beyond 2014.

"We agreed that this transition to Afghan lead for security would begin in 2011 and that it would conclude in 2014," Obama said at the summit in Chicago, his hometown, as he and other Nato leaders and partners wanted to reiterate confidence in Afghanistan's ability to take the lead for its own security next year.

"At the same time, we said that we would seek a long-term partnership with Afghanistan and the Afghan people. Over the past two years, we have made important progress. Our forces broke the Taliban's momentum. More Afghans are reclaiming their communities. Afghan security forces have grown stronger and the transition that we agreed to in Lisbon is well underway."

At the Lisbon summit in 2010, the 28 Nato members agreed on a framework for transition in Afghanistan that would allow them to wind down the war.

"We come together as 50 nations, Nato's allies and partners that make up the International Security Assistance Force (ISAF) in Afghanistan," Obama said in his speech. "The presence of so many leaders and nations illustrates once again that this is a truly international mission, and that is because the region and the world have a profound interest in an Afghanistan that is stable, that is secure, and that is not a source of attacks on other nations," he said.

The war is increasingly unpopular in several countries and protesters in Chicago showed their opposition in largely peaceful demonstrations that were at times sabotaged by anarchists.

However, Obama wanted to assure everyone, including those who started making statements about an earlier-than-agreed withdrawal, that the time frame is well set and will be respected.

"Today, we will set a goal for Afghan forces to take the lead for combat operations across the country in 2013 so that ISAF can move to a supporting role. This will be another step toward Afghans taking full lead for their security as agreed to by 2014 when the ISAF combat mission will end," he said.

Obama highlighted the need to work on the post pullout phase.

"Today is also an opportunity to ensure our hard-won progress is preserved. The Strategic Partnership Agreement that President Karzai and I signed in Kabul ensures that as Afghans stand up they will not stand alone. Today, we can agree on Nato's long-term relationship with Afghanistan beyond 2014, including our support of Afghan security forces," he said.