Elon Musk says Twitter will permanently suspend any account that impersonates another - unless it clearly states it is a "parody".

The social media platform's new owner issued the warning after some celebrities changed their Twitter display names - not their account names - to "Elon Musk" in reaction to the billionaire's decision to offer verified accounts to all users for $8 month.

Comedian Kathy Griffin had her account suspended on Sunday for switching her display name to Musk's.

Actor Valerie Bertinelli did the same before switching it back to her real name. But first, she posted a series of tweets in support of Democratic candidates.

Comedian Sarah Silverman also appeared to have her account locked as she shared a screenshot of her Twitter page with the display name "Sarah K Silverman".

Musk said Twitter previously issued a warning before suspension, but as the social media giant is rolling out widespread verification, there will be no warning as well as "no exceptions."

On the topic of banned accounts, Musk last week said they will not be allowed back onto Twitter until the social media platform has "a clear process for doing so."

Creating such a process would take at least a few more weeks, Musk had tweeted, giving more clarity about the potential return of Twitter's most famous banned user, former US President Donald Trump.

The new timeline implies Trump will not return in time for the midterm elections on 8 November.

Earlier on Sunday, the New York Times reported Twitter is delaying the rollout of verification check marks to subscribers
of its new service until after Tuesday's midterm elections.