Users will now see a little video icon in the top right corner of a conversation screen in the Messenger app. The launch comes as the social media giant strives to bolster the features on its mobile service and grow the user base on its standalone platform.
Messenger currently has 600 million users and Facebook is hoping it can grow this number to match the 1.44 billion monthly active users of the Facebook website.
Facebook spun off Messenger as a standalone app in 2011. That that same year it announced a partnership with Skype to develop video calling, although this time round, Facebook company appears to be going it alone. The video-calling feature was rolled out on the desktop version of Messenger earlier this month.
Facebook and its Instagram app account for more than one out of every five minutes that U.S. users spend on mobile, COO Sheryl Sandberg said last week. The social network's CEO Mark Zuckerberg hinted earlier this year at further developments for Messenger and video calling is the latest in a line of features as the company continues its mobile focus.
Last week, the Menlo Park, CA-based company released an , which replaces the native Android dial screen when users want to make a phone call. It harnesses contact information from Facebook friends to identify who is calling and highlights Facebook's desire to be at the center of mobile communication.
Last month, the company also launched a feature that allows people to send money to each other via the Messenger app.
Video calling in Messenger launched today for iOS and Android users in 18 countries including the U.S., Canada and the U.K. The feature will be rolled out in other regions "over the coming months", Facebook said.