The billionaire businessman - who bought the micro-blogging site Twitter in 2022 for $44 and has since made several changes to the platform - has previously exerimented with a 'Not A Bot' subscription in New Zealand and the Philippines, which charged users around $1 to prove they are human.

Now, he has suggested the charge could get a wider rollout, which would see new users having to pay to post, like, bookmark and reply.

Responding to speculation around the idea, he replied on X: "Unfortunately, a small fee for new user write access is the only way to curb the relentless onslaught of bots.

"Current AI (and trolls farms) can pass 'are you a bot' with ease."

Last month, Musk announced that users with more than 2,500 verified subscribers will benefit from Premium features without paying a penny.

In addition, those with 5,000 or more followers will get to experience Premium+ features, including access to Grok, Musk's ChatGPT rival.

He posted to the site: "Going forward, all X accounts with over 2500 verified subscriber followers will get Premium features for free and accounts with over 5000 will get Premium+ for free."

Days earlier, Musk revealed he was making xAI's chatbot Grok available to X's Premium subscribers "later this week".

He posted to X alongside a video explaining how to start a conversation with Grok: "Later this week, Grok will be enabled for all premium subscribers (not just premium+)."

It costs $8 a month or $84 a year to upgrade to a Premium account.