Pakistan's army chief Raheel Sharif visited Kabul for talks with Afghan President Ashraf Ghani and the two vowed to fight "terrorism and extremism" together.
Sharif arrived on December 17, one day after a massacre at a Pakistani school in Peshawar left some 148 people dead, mostly schoolchildren.
The Pakistani Taliban claimed responsibility.
After his meeting with Sharif, Ghani said in a statement, "The time has come for Afghanistan and Pakistan to work together in sincerity and jointly take effective actions against terrorism and extremism."
Sharif and the head of Pakistan's main intelligence agency, ISI, were also due to meet with NATO commander General John Campbell during the visit.
Afghanistan has also been facing a spike in terrorist attacks in recent weeks, including a suicide bombing in the southern Kandahar Province during the morning of December 17.
Based on reports by AFP and "Dawn"