On Tuesday, Baroness Casey is expected to publish her report about the Met’s culture and standards - having been appointed to the task after the murder of Sarah Everard by serving officer Wayne Couzens.
The BBC has said it understands the review will heavily criticise the Met for a tolerance of wrongdoing - including issues around racism, sexism and homophobia.
Speaking ahead of the report’s publication, Mr Khan said: “One of the reasons why I asked for this review was because of my concerns around the systemic cultural issues, after a series of scandals.
“Let’s wait and see what Dame Louise Casey says. We have a new commissioner now and it’s important that he has the right information about the police service, but also, that he is somebody who believes there should be a reform of the police service.”
He added: “I’ve not seen the final report, I understand it’s out next week. The key thing is for nobody to be in denial about some of these systemic issues there are.
“But also to win back the trust and confidence of Londoners whose support we need, because we police consent.
“We need them to come forward and be witnesses, and if they’ve been the victim to come forward - and also to join the police service.”
Sir Mark Rowley was appointed the Met’s chief in September and has pledged to turn around the beleaguered force.
The interim Casey review published in October found hundreds of Met officers had been getting away with misconduct.
It found many claims of misogyny, racism and homophobia had been badly mishandled.
Sir Mark apologised and admitted there were officers still serving who should have been sacked, and has since called for additional powers to sack rogue officers.
The Met Police has said in a statement "the report will play an important role in informing and shaping our work to deliver 'More Trust, Less Crime and High Standards'.
"It will be published next week which will be the appropriate point for us to respond in further detail."