Peterson tested positive for synthetic testosterone in March during a random drugs testing ahead of their proposed May 19 bout for the WBA and IBF light-welterweight championship in Las Vegas.
British fighter Khan has now admitted that he is ready for a new challenge this summer.
Khan wrote on his Twitter account: "The fight is off! Sorry everyone the only person to blame is @kingpete26(Peterson's account).
"I'll be looking for a opponent to fight June 30th."
Peterson's camp are reportedly preparing medical records to ensure that Peterson can retain his boxing licence.