U.S. President Barack Obama and Pakistani Prime Minister Nawaz Sharif will meet Wednesday at the White House. The meeting comes a day after human rights organizations criticized the United States for the secrecy surrounding its drone campaign in Pakistan.
The drones are expected to be high on the agenda at Wednesday's talks .
In an address at the U.S. Institute of Peace in Washington on Tuesday, 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."
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 International 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 disagree with claims that the drone strikes violate international law.
Amnesty International'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 were killed 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.