Washington - CIA director Mike Pompeo pulled out of a Harvard forum and former acting director Mike Morrell quit the university on Thursday to protest its appointment of convicted intelligence leaker Chelsea Manning as a visiting fellow.Pompeo, who was scheduled to speak late on Thursday at a forum at Harvard's Kennedy School of Government, cancelled at the last minute following news of Manning joining the prestigious institution.Labelling Manning an "American traitor", Pompeo said in a statement that his conscience would not allow him to "betray the trust" of the Central Intelligence Agency staff by appearing to support Harvard's decision by joining the event."Ms Manning betrayed her country and was found guilty of 17 serious crimes for leaking classified information to Wikileaks," he said in a statement."Ms Manning stands against everything the brave men and women I serve alongside stand for."Pompeo, who attended Harvard Law School, said it was "shameful" that Harvard gave Manning's actions its "stamp of approval".Earlier Morrell said he was stepping down as a senior fellow at The Belfer Centre, part of the Kennedy School, for the same reason.Manning was one of several people, including former White House Press Secretary Sean Spicer, and Hillary Clinton campaign manager Robby Mook, named as Kennedy School visiting fellows on Wednesday for the 2017-2018 year.Manning, then known as Bradley Manning, was convicted of espionage and other charges in 2013 for leaking his hundreds of thousands of secret US diplomatic communications and other documents to WikiLeaks.Sentenced to 35 years in prison, the former army intelligence analyst had her sentence commuted in May 2017 by President Barack Obama to seven years dating to her 2010 arrest and she was freed. While in prison Manning transitioned from male to female.