WhatsApp has introduced video calling to users of the instant messaging app for the first time.

The Facebook-owned service, which has more than one billion users worldwide, will now enable users to make video calls to contacts across iPhone, Android and Windows Phone devices.

"We're introducing this feature because we know that sometimes voice and text just aren't enough," WhatsApp said in announcing the feature.

"There's no substitute for watching your grandchild take her first steps, or seeing your daughter's face while she's studying abroad. And we want to make these features available to everyone, not just those who can afford the most expensive new phones or live in countries with the best cellular networks.

"Over the years we've received many requests from our users for video calling, and we're excited to finally offer this feature to the world."

WhatsApp, which was bought by Facebook for more than £11 billion in 2014, follows Google's new Duo app, Facebook Messenger and Apple's FaceTime among others in offering video calling to users.

However, WhatsApp believes it is less restrictive than other services and has said its video calling will work "across thousands of device and platform combinations all over the world".

The introduction of video calling follows a recent camera update that enables users to add emoji and sketches to photos for the first time - challenging photo app Snapchat in the process.