Chicago: President Barack Obama met briefly on the sidelines of the NATO summit with Pakistani President Asif Ali Zardari and Afghan President Hamid Karzai.
The meeting comes amid tensions over Pakistan`s closure of key transit routes used by NATO to send supplies to troops in Afghanistan. Pakistan closed the routes in November in response to a US airstrike that killed two dozen Pakistani soldiers.
The three leaders met after a larger meeting focused on Afghanistan`s future.
US and Pakistani officials have been in talks to reopen the supply lines, but the negotiations are stalled.
US officials say that while they expect the issue to be resolved, they did not believe that would happen while leaders were gathered in Chicago for the NATO summit.