CHICAGO (AP) — President Barack Obama expressed confidence in Afghanistan's ability to take the lead for its own security next year, as NATO leaders huddled Monday for talks aimed at paving the way for the deeply unpopular war's end.

The alliance leaders, meeting in Obama's hometown, were solidifying plans for Afghan security forces to take control in combat next summer, with NATO sliding into a support role. Obama said the transition was "the next milestone" in NATO's plans for bringing the nearly 11-year long war to a close.

"This will be another step toward Afghans taking full lead for their security as agreed to by 2014 when the ISAF mission will end," Obama said as he opened a meeting of NATO leaders and partner countries who have participated in the war.

NATO leaders were joined by representatives of other nations that have a stake in the war, including Afghan President Hamid Karzai and Pakistani President Asif Ali Zardari.

Zardari's presence has cast a shadow over the summit. The U.S. and Pakistan remain at odds over Pakistan's closure of key routes used to send supplies to NATO troops in Afghanistan. Pakistan closed the supply lines in November following a U.S. airstrike that killed two dozen Pakistani soldiers. While both sides have indicated the issue will be resolved, no deal is expected to be reached during the NATO meetings.

Obama thanked other nations in Central Asia and Russia for their role in providing "critical transit" for supplies, but pointedly did not mention Pakistan.