CIA drone strikes on targets in Pakistan violate its national sovereignty and have resulted in far more civilian casualties than the U.S. government has recognized, a special U.N. human rights envoy has reported after a secret investigation.

Ben Emmerson, the U.N. special rapporteur on human rights and counterterrorism, met with Pakistani government officials for three days and came away supporting their long-stated view that they do not consent to the remote-fired missile campaign that is the centerpiece of U.S. strategy to eliminate a wide range of Islamic militants.

This contradicts Washington's position that the Pakistani military and intelligence services have at least tacitly supported the strikes, which began in 2004 and have significantly escalated since U.S. President Barack Obama took office. At one point earlier in the campaign, the two nations shared intelligence on militant targets, but Pakistani officials vehemently deny they are still doing so.