Services including PayPal, its Venmo unit and the disappearing-photo app Snapchat let you beam money to friends and family using smartphones linked to bank accounts or credit cards.

Facebook's entry, announced on March 17, is free, works with debit cards and is available on Apple and Android mobile devices and on desktop computers.

The world's largest social network will process the payments and emphasized the service's security features.

Facebook will likely expand internationally after the service becomes available to US users over the coming months.

To send money, Messenger users can tap a new "$" icon that's next to the buttons that let you send photos, stickers or a thumbs up sign. Then, enter the amount you want to send, tap "pay" on the top right corner and enter your debit card number. To receive money for the first time, enter the card number.

Once you add your card number, you can create a pin code that you will need to enter the next time you want to send money. On Apple devices that have Touch ID, you can enable this instead and authorize transactions using your fingerprint.

To help allay concerns about security, Facebook noted that it handles more than a million payments transactions on its site every day for its advertisers and game players.

Its payments systems are stored separately from other parts of the Facebook network and receive additional monitoring and control, the company said in a blog post on March 17.