He pitched the app as a "friendly" rival to Twitter, which was bought by Elon Musk in October.

Experts say Threads could attract Twitter users unhappy with recent changes to the platform.

Threads allows users to post up to 500 characters, and has many features similar to Twitter.

Earlier, Mr Zuckerberg said keeping the platform "friendly... will ultimately be the key to its success".

But Mr Musk responded: "It is infinitely preferable to be attacked by strangers on Twitter, than indulge in the false happiness of hide-the-pain Instagram."

When asked on Threads whether the app will be "bigger than Twitter", Mr Zuckerberg said: "It'll take some time, but I think there should be a public conversations app with 1 billion+ people on it.

"Twitter has had the opportunity to do this but hasn't nailed it. Hopefully we will."

The launch has had a warm response online, with one person telling the BBC they saw Threads as a "much-needed competitor" to Twitter.

Competitors have criticised the amount of data the app might use. This may include health, financial, and browsing data linked to users' identities, according to the Apple App Store.

Some users have also expressed concern that it is not possible to delete your Threads profile without deleting the associated Instagram profile. Meta told the BBC: "At this time, you can't delete your Threads profile without deleting your Instagram account. This is something we're working on. In the meantime, you can deactivate your Threads profile at any time.

"Deactivating your Threads profile will not deactivate your Instagram account".

Deactivation will mean your Threads profile, your posts and interactions with others' posts won't be visible, the firm added.

Users can download and delete Threads data by visiting their Instagram settings, Meta says.

Threads is now available to download in over 100 countries including the UK, but not yet in the EU because of regulatory concerns.