In a statement, Asif said terrorists had killed Pakistani soldiers in a cowardly attack on security forces in North Waziristan and it was the right of the forces to hit back against aggressors.
"We would not cede our right to defend," he said.
At least 33 militants, including some Uzbeks, have been killed in fierce clashes with the army in North Waziristan Agency since Wednesday night.
Media reports said three civilians were also killed in the fighting.
The clashes erupted after the militants ambushed a security forces convoy that was evacuating soldiers injured in a suicide attack on Khajori check post on Wednesday.