The attacks took place in the Shawal area of the North Waziristan tribal region, where the army has been waging an offensive against militant hideouts since June last year.
“In precise aerial strikes, 40 terrorists were killed this afternoon in Shawal,” the military said in a statement.
It said it had reports that several others were wounded, without giving details.
Pakistan has been battling a homegrown Islamist insurgency for over a decade.
The military says more than 2,800 militants have been killed since the launch of the latest offensive named Zarb-e-Azb.