U.S. President Barack Obama says the Chicago NATO summit closes with a clear road map for the alliance's role in Afghanistan.

Wrapping up the two-day summit Monday, Mr. Obama said NATO members are unified behind a plan to wind down the war so the Afghan government can take the full lead for its own security by 2014.

But he said there is never what he called an optimal point, where things can be called perfect. Mr. Obama said the transition can be a very messy process, and that he anticipates bad moments between now and 2014.

The president said the timetable is sound and responsible, and that NATO will continue training and advising Afghan forces as they grow stronger.

Mr. Obama said NATO emerges from the Chicago summit stronger and more capable, and remains the hub of global security.

About 130,000 foreign troops remain in Afghanistan as part of the international coalition. Newly elected French President Francois Hollande has reaffirmed his pledge to pull out all French combat forces by the end of this year. France has about 3,300 troops in Afghanistan – the fifth-largest group in the coalition.

Funding for Afghan security forces after 2014 could cost $4.1 billion a year, with the United States expected to cover a large portion of the bill.

Leaders from more than 50 nations opened the summit on Sunday with a moment of silence to pay tribute to thousands of coalition troops killed or wounded during the Afghan war.

Summit participants included Pakistani President Asif Ali Zardari, who was invited last week after Islamabad suggested it would soon reopen ground supply routes to U.S. and NATO forces in Afghanistan.

Mr. Obama briefly spoke with Mr. Zardari Monday, telling him that Pakistan has to be part of the solution in Afghanistan.

Pakistan closed its borders to NATO supply convoys after U.S. airstrikes mistakenly killed 24 Pakistani soldiers along the Afghan border in November. The incident brought U.S.-Pakistani relations to a new low. But the two sides are now engaged in intense negotiations to finalize a deal to reopen the routes. Pakistan is seeking heavy taxes on future NATO convoys, a condition diplomatic sources say is hindering the talks.