Twitter has announced that TweetDeck, a popular program that allows users to monitor several accounts at once, will be available only to "verified" users from next month.

The social media firm, bought by billionaire Elon Musk last year, has been thrashing around for ways to make a profit, cutting staff and ramping up its paid-for subscriptions.

Twitter's verified users are mostly those who have paid to receive a blue check mark, though Musk has gifted the check mark to some users and others have it as a legacy from the previous regime.

TweetDeck, launched more than a decade ago, shows messages in columns and its search and posting functions operate differently to the website or the app.

The firm said in a support message on Monday that it was launching a new version of TweetDeck with various new functions.

"In 30 days, users must be Verified to access TweetDeck," the message said.

A series of changes to the way Twitter is run left many TweetDeck users unable to see posts on the weekend.

Twitter bought London-based TweetDeck in 2011, with technology media putting the price tag at $40 million at the time.