U.S. Secretary of State John Kerry has arrived in Pakistan on an unannounced visit to discuss security cooperation in the fight against militants.
A Pakistan Foreign Ministry official said Kerry landed at Nur Khan Airbase in Rawalpindi, near the capital, Islamabad, on January 12.
Kerry met Prime Minister Nawaz Sharif to discuss political and security issues, the official said.
The huge challenge Pakistan faces from militants was underscored home when Taliban assailants attacked an army-run school in Peshawar on December 16 and killed more than 150 people, almost all of them children.
The visit by Kerry, who arrived from India, coincides with the reopening of the Peshawar school and others across Pakistan after an extended break following the attack.
It also comes after the withdrawal of most foreign troops from Afghanistan, where the NATO combat mission formally ended last month.