Islamabad, Jun 9 (IANS): Drone attacks by the US in Pakistan's militancy-hit northwest tribal region "must stop" as they were violating the country's sovereignty and international laws, Prime Minister Nawaz Sharif has said.

The Pakistan Foreign Office Saturday summoned US Charge d' Affaires Richard Hoagland to lodge a strong protest over a drone strike in North Waziristan Friday that killed at least seven people.

"Drone attacks must stop. We have protested many a time. This is simply unacceptable," Dawn News quoted Sharif as saying at a meeting with German Foreign Minister Guido Westerwelle.

Westerwelle called on the prime minister along with a six-member delegation to discuss bilateral relations.

On Saturday, US diplomat Hoagland was summoned by Pakistan's Minister of State for Foreign Affairs Tariq Fatemi, the foreign ministry said.

The foreign office conveyed to the US official that Pakistan strongly condemns the drone strikes, and considers them a violation of the country's sovereignty and territorial integrity.

Pakistan has consistently maintained that the strikes were counter-productive, led to deaths of innocent civilians and have human rights and humanitarian implications, it said.