The key to preventing child sexual exploitation is stopping young people who are "determined to put themselves at risk", from running away from care homes, the chief constable of Greater Manchester Police said.
Sir Peter Fahy insisted that the police had learned lessons after an investigation highlighted "significant failures" in the handling of widespread abuse in Rochdale.
The chief constable rejected calls from ex-detective Margaret Oliver for a full independent inquiry into the force's actions.
"The issue is that we still haven't solved the key issue behind CSE (child sexual exploitation) which is: how do you protect vulnerable young people who are determined unfortunately to put themselves at risk, that don't understand the degree to which they are making themselves vulnerable," he told BBC Radio 4's Today.
Asked if he saw the problem as being children putting themselves at risk, he went on: "Yes absolutely. Because of their upbringing, because of their difficult situation and because they are in care, every single day we have large numbers running away.
A former Greater Manchester Police detective says a report into the handling of Rochdale abuse does not go "nearly far enough".
Speaking to ITV News, a victim of child sex abuse in Rochdale claims some police officers had "completely lied" about events.
Greater Manchester Police (GMP) issues an apology to victims of the Rochdale child sex abuse scandal.