The update means that users will be able to send a short voicemail-style message to their friends, either through their own app or the desktop site.
Further VoIP functionality, which will enable users to call Facebook friends directly for free, is currently being tested in Canada, and will be rolled out shortly.
Although Facebook piloted VoIP calls in 2011, powered by Skype, this feature has rejected the Microsoft-owned company in favour of in-house technology.
Meanwhile, Samsung has launched ChatON 2.0, a cross-platform IM app which includes text, voice and video chat which works across smartphones, tablets, and desktop. Users can connect five connected devices to their account, and can send images or videos via its Trunk storage functionality.
ChatON is monetised through its 'Special Buddy' feature, which pushes offers, updates and news feeds from third-party vendors to users in real-time.