US and Pakistani officials say the CIA station chief who ran operations in Pakistan during the raid that killed Osama bin Laden is leaving his post due to illness.

His departure was first reported by ABC News. The man cannot be named because he is undercover.

The station chief guided operations through a troubled time in US-Pakistani relations.

Documents released by WikiLeaks showed Pakistani officials backing CIA drone strikes in their territory against al-Qaida, while CIA contractor Raymond Davis' killing of two Pakistani men he said were trying to rob him frayed relations. Then came the May 2nd raid on bin Laden's compound.

American officials say the outgoing chief clashed with Ambassador Cameron Munter, who objected to CIA drone strikes during diplomatic negotiations. Officials spoke anonymously to discuss personnel matters.