The commander of NATO-led troops in Afghanistan, U.S. General John Allen, visited Pakistan on June 27 for talks on reopening NATO supply routes from Pakistan to Afghanistan and other issues.
Allen went straight into a meeting with Pakistani army chief General Ashfaq Kayani in Rawalpindi, before flying out of the country.
There was no immediate comment from NATO's International Security Assistance Force (ISAF), but earlier reports said Allen was to raise concerns about attacks in Afghanistan blamed on the Haqqani network, which NATO believes is controlled from inside Pakistan.
In an attack last week blamed on the network, some 20 people were killed when militants stormed a Kabul hotel.
The NATO supply routes to Afghanistan from Pakistan have been closed since November 2011, when a NATO air strike killed 24 Pakistani soldiers.
Washington has rejected Pakistani demands for an apology.
Based on reporting by AFP and Reuters