The drone strike was carried out on Saturday in the Mana area of Shawal region of North Waziristan district.
Six 'militants', including foreigners, were killed in the drone strike while two others were reported injured.
Pakistan's Foreign Office (FO) in a statement today termed the strike a violation of its sovereignty.
"We condemn such strikes which are a clear violation of Pakistan's sovereignty and territorial integrity," it said.
FO also said such strikes "generate distrust among the local populace" at a time when Operation Zarb-e-Azb was moving ahead decisively and the focus of the government was shifting towards rehabilitation of the civilian population.
The US has persisted with drone strikes despite protests by Pakistan, as they help in eliminating militants in areas which are inaccessible by land for the US army.