Facebook will turn off its messaging application in its main mobile app to force users to download Messenger, its standalone messaging app, said The Verge tech website.

Facebook campaign to increase usage of its Messenger app is forcing it to kill off the chatting feature for its main Facebook app, keeping the messages button intact but automatically sending users to Messenger when it's tapped.

Facebook began notifying select European users of its main Facebook app that in two weeks' time, messaging will be disabled. Users will then be prompted to download Messenger if they have not already. Facebook confirmed that this is not a test and will soon begin rolling it out worldwide. 

Android phones with particularly low memory will be exempted. Also exempted for the time being are Windows Phone and tablet users. Facebook Paper, the company's new news-focused redesign, will also keep in-app messaging.

Analysts said the process of moving from one app to the next is relatively smooth and quick. On iOS, the Messenger interface includes a blue banner that switches users back to the main Facebook app when tapped.

This is not the case on Android  nor does Facebook's main app force Android users to open up Messenger even if they have it installed. It's unclear if Facebook's Messenger changes will be the same across iOS and Android. 

On iOS but not on Android, Facebook already prompts users to switch over to its Messenger app to chat with friends.

For the time being, however, Facebook lets you message friends within its main app using its nicely designed Chat heads feature.