WhatsApp to introduce voice calls in second quarter

WhatsApp intends to add voice calling to its free text messaging service in the second quarter of 2014, it was announced on Monday.

The announcement answers some of the questions behind WhatsApp's recent purchase by Facebook for a price of 19 billion U.S. dollars.

Addressing the opening day of the Mobile World Congress in Barcelona, WhatsApp founder and chief executive Jan Koum confirmed the aim was to introduce voice calls, initially on the iPhone and Android.

Windows Phones and BlackBerrys will be included at a later date.

"We are adding voice to WhatsApp so that people can stay in touch with friends and loved ones no matter where they are in the world," said Koum.

"We use the least amount of bandwidth and we have optimized it. We have made sure the quality is there," Koum said, adding there were no other plans to change his company in the new Facebook era.

"WhatsApp will continue to function as if it is an independent company without adding to its small staff of just 55 employees as the intention is for it to be able to remain as adaptable as possible," he said.

WhatsApp Messenger is a cross-platform mobile messaging application which allows people to exchange messages without having to pay for short message service, according to the company's website.