Pakistani Prime Minister Nawaz Sharif has reiterated his country's demand for an end to U.S. drone strikes inside Pakistan.
In an address at the U.S. Institute of Peace in Washington Tuesday, Mr. Sharif said he wants to see U.S.-Pakistan relations improve "but the issue of drones has become a major irritant in our bilateral relationship."
"The use of drones is not only a continual violation of our territorial integrity but also detrimental to our resolve and efforts at eliminating terrorism from our country."
His comments came as the Britain-based rights group Amnesty International called on the U.S. to end the secrecy surrounding its drone campaign in Pakistan.
In a report released Tuesday, Amnesty said the U.S. "appears to have committed very serious" human rights violations that might even amount to war crimes.
White House Spokesman Jay Carney said the U.S. strongly disagrees with claims that the drone strikes violate international law.
"U.S. counterterrorism operations are precise, they are lawful, and they are effective, and the United States does not take lethal strikes when we or our partners have the ability to capture individual terrorists."
Amnesty's report outlines 45 missile strikes by pilotless planes in Pakistan's North Waziristan tribal territory from January 2012 to August 2013. It says in one case, a 68-year-old grandmother was killed while in a field picking vegetables. In another, it said, 18 laborers died by a drone strike as they prepared to eat their evening meal.
Pakistani leaders say they strongly oppose the drone strikes, but some critics believe the operations aimed at suspected al-Qaida and Taliban operatives are part of a secret agreement under which Pakistan tacitly approves the U.S. strikes.
Amnesty International is calling on the United States and Pakistan to publicly disclose all information possible about the strikes. The report says locals in the area where the drones strike live in constant fear of violence from all sides.
U.N. Special Rapporteur Ben Emmerson has also called on the United States for more transparency. In preliminary findings last week, he quoted Pakistani officials as saying the drone attacks have killed at least 400 civilians.
U.S. authorities have offered little public information about the drone strikes but say they are carefully planned to avoid civilian casualties and have killed key al-Qaida operatives.