Belfiore was speaking at Microsoft’s press & analyst event, taking place in Barcelona ahead of the Mobile World Congress tradeshow which kicked off today. No specific date was announced but it was told that it's progressing well enough.

Belfiore argued that 2013 was a good year for Microsoft’s mobile ecosystem, noting particularly growth in handset shipments in markets such as UK and Italy. He said that the Windows Phone Store now had over 240,000 apps with an average of 500 apps added ever day. With key additions such as Instagram, Vine, Waze and Mint under its belt recently, Microsoft announced that Facebook Messenger will be available in "the coming weeks".

Belfiore said that Windows Phone has recently been recognized as the fastest growing OS by IDC with 91 percent year-over-year growth in 2013.

Microsoft also announced a new partnership with Qualcomm, under which it will be building Windows Phone devices through the well-established Qualcomm Reference Design (QRD) program. This would make it easier for OEMs to make Windows Phone-based devices.