Facebook founder Mark Zuckerberg said on Wednesday that the social platform is turning from a "digital town square" to a secure, private and small-scale messaging network.

"I believe the future of communication will increasingly shift to private, encrypted services where people can be confident what they say to each other stays secure and their messages and content won't stick around forever," Zuckerberg wrote on his Facebook page.

"This is the future I hope we will help bring about.

Zuckerberg said that "people increasingly want to connect privately in the digital equivalent of the living room", adding that Facebook will move away from being a public platform to emphasize smaller-scale conversations that are secure and encrypted.

"Today we already see that private messaging, ephemeral stories, and small groups are by far the fastest growing areas of online communication," he said.

"Many people prefer the intimacy of communicating one-on-one or with just a few friends. People are more cautious of having a permanent record of what they've shared. And we all expect to be able to do things like payments privately and securely."

"Today if you want to message people on Facebook you have to use Messenger, on Instagram you have to use Direct, and on WhatsApp you have to use WhatsApp," he wrote. "We want to give people a choice so they can reach their friends across these networks from whichever app they prefer."

Zuckerberg stressed that he plans to build his new vision for Facebook the way WhatsApp was developed: focus on the most fundamental and private use case — messaging — make it as secure as possible, and then build more ways for people to interact on top of that, including calls, video chats, groups, stories, businesses, payments, commerce, and ultimately a platform for many other kinds of private services.

"There is an opportunity to build a platform that focuses on all of the ways people want to interact privately. This sense of privacy and intimacy is not just about technical features — it is designed deeply into the feel of the service overall," he wrote.

"In WhatsApp, for example, our team is obsessed with creating an intimate environment in every aspect of the product. Even where we’ve built features that allow for broader sharing, it’s still a less public experience. When the team built groups, they put in a size limit to make sure every interaction felt private."

Zuckerberg noted that, in a few years, he expects future versions of Messenger and WhatsApp to become the main ways people communicate on the Facebook network.

"We’re focused on making both of these apps faster, simpler, more private and more secure, including with end-to-end encryption."