Snapchat has launched a surprise update, drastically overhauling their messaging system in order to battle their rivals Facebook.

The new update allows you to text friends and do live video calls.

The company announced the new update to users through a video sent to all their active users through the app itself.

"Until today, we felt that Snapchat was missing an important part of conversation: presence. There's nothing like knowing you have the full attention of your friend while you're chatting. We could not be more thrilled to announce Chat," the company writes in a blog post.

You can swipe right on a friend's name in your Snapchat inbox to start chatting. When you leave the chat screen, messages viewed by both you and your friend will be cleared, continuing Snapchat's apparent commitment to disappearing content.

Snapchat has 40 million users worldwide, and has increasingly come into competition with social media giant Facebook over shares of the mobile app market.

The video call function also brings it into competition with Skype and Apple's FaceTime.

Early last month, Facebook began to notify its mobile app users that in the near future if they wish to chat to their friends then they will need to download the company's new Messenger app instead.

Facebook recently sent out a clear message out to its competitors by spending a huge $19 billion [£11.39 billion] to acquire mobile messaging startup WhatsApp.

The deal gave Facebook access to some 450 million users of the service and helped it to tap further into the messaging space. This was seen at the time as a direct challenge to Snapchat's primacy in the messaging app stakes.

Facebook has not so far commented on the update.