The head of a UN team investigating US drone strikes in Pakistan has said that Islamabad does not consent to them and sees them as a territorial violation. American officials say privately that co-operation with Pakistan has not ended altogether - despite a cooling of relations - and key Pakistani military officers and civilian politicians continue to support the strikes. It is estimated that between 2004 and 2013, CIA drone attacks in Pakistan killed up to 3,460 people. About 890 of them were civilians and the vast majority of strikes were carried out under the President Barack Obama's administration. The position of the government of Pakistan is quite clear," Mr Emmerson said on Friday. "It does not consent to the use of drones by the United States on its territory and it considers this to be a violation of Pakistan's sovereignty and territorial integrity." The drone campaign "involves the use of force on the territory of another state without its consent", he said. Furthermore Pakistan believes that drone strikes are radicalising a new generation of militants, he said, when it was capable of fighting Islamist extremists in the country by itself. The UN special rapporteur said that as a matter of international law, drone strikes were only lawful if they took place at the express request of the country concerned.