Pakistan: Hostage deaths show US drone risk
The deaths of two Western hostages in a US drone strike shows the "risk and unintended consequences" of using such a tactic, Pakistan has said.
Islamabad offered its condolences to the families of US consultant Warren Weinstein and Italian aid worker Giovanni Lo Porto.
The two men were accidentally killed in a counter-terrorism operation in January, the US has admitted.
The drone strike targeted an al-Qaeda hideout on the Afghan-Pakistan border.
They died along with al-Qaeda leader Ahmed Farouq.
Pakistan said in a statement that "having lost thousands of innocent civilians in the war against terrorism" it fully understood "this tragic loss and stands with" the families of the two hostages.
"The death of Mr Weinstein and Mr Lo Porto in a drone strike demonstrates the risk and unintended consequences of the use of this technology that Pakistan has been highlighting for a long time," the statement added.
American drone strikes in Pakistan's tribal belt are extremely unpopular with Pakistanis; many view them as violation of their country's sovereignty.
While Pakistani officials publicly condemn the drone strikes, correspondents say they have tacitly endorsed these strikes for years.
Mr Obama on Thursday said he took "full responsibility" for the operation, which was launched in the belief that the target was an al-Qaeda compound with no civilians present.
The White House announced that two other US citizens - thought to be al-Qaeda members - were also killed in drone strikes.
Ahmed Farouq was killed in the same raid that caused the deaths of Mr Weinstein and Mr Lo Porto, it said, and Adam Gadahn, once regarded as a spokesman for the militant group, was killed in a separate strike.
The BBC has been told that the attack which killed the hostages took place on 15 January in the Dabar Miami area, in the Shawal region of North Waziristan.
An al-Qaeda statement on 13 April confirmed Farouq's death but made no mention of the hostages, the BBC's M Ilyas Khan in Islamabad reports.