Mr Musk’s comments, which came in a response to an account posting about the changes, suggest that trial could now be rolled out more widely.
“Unfortunately, a small fee for new user write access is the only way to curb the relentless onslaught of bots,” he said.
“Current AI (and troll farms) can pass ‘Are you a bot?’ with ease.
“The onslaught of fake accounts also uses up the available namespace, so many good handles are taken as a result.”
In a separate reply to another account which questioned the approach, Mr Musk added that the fee may only be in place for the first three months after a new user has joined the platform.
The billionaire said eradicating fake and bot accounts was a key priority for him when he took over the social media platform in late 2022.
But many users have reported seeing an increase in spam content, which has been blamed in part on Mr Musk’s substantial cutbacks to staff, including the firm’s content moderation team.
The revamp to X’s verification system, which means anyone can now pay to be labeled as a verified user and have their posts and replies placed more prominently on the site, has also been blamed for an increased prominence of spam content.
Mr Musk has previously suggested that all users could eventually have to pay to use X.
Since his takeover, it has been reported that the platform has seen substantial revenue decline, with advertisers abandoning it over concerns about Mr Musk’s belief in “absolute free speech” and his tolerance of more controversial content.
It has led the company to turn to subscription options – including X Premium, which enables users to pay to be verified – in order to open up new income streams