The killing of journalist Saleem Shahzad was 'sanctioned' by the Pakistan government, said a top US official.
Admiral Mike Mullen, chairman of the Joint Chiefs of Staff, said: 'It was sanctioned by the (Pakistan) government.'
'I have not seen anything to disabuse the report that the government knew about this,' he said during a Pentagon briefing.
Admiral Mullen is the first American official to publicly accuse Pakistan of the kidnapping, torture and death of 40-year-old Saleem Shahzad, reported the New York Times.
Shahzad, 40, was kidnapped in Islamabad May 29 and his body, bearing marks of severe torture, was found dumped in a canal in Punjab province two days later.
He is widely believed to have been seized by intelligence officials for alleging in an article that terrorists attacked a key naval base in Karachi May 22 after the navy refused to free sailors held for suspected militant links.
Admiral Mullen said he could not specifically tie Shahzad's death to the Inter-Services Intelligence, although Obama administration officials believe that the ISI ordered the killing.
The ISI has denied that it killed Shahzad.
A military official later said that Admiral Mullen was 'appalled' at learning of the circumstances behind Shahzad's death.
A doctor who conducted the post-mortem examination said the journalist had sustained 17 lacerated wounds, a ruptured liver and two broken ribs.
Pakistan's Ambassador to the US, Husain Haqqani, reacting to Admiral Mullen's remarks, said Pakistan has appointed a commission to probe the death.
'Any evidence that our American friends have should be shared with that commission,' Haqqani was quoted as saying.
'We are as interested in getting to the bottom of this matter as anyone else in the world, given our concern about human rights.'