Messaging service WhatsApp will end its support by the end of this year to BlackBerry phones and those powered by Nokia's Symbian operating system.
The Facebook-owned company has over a billion users globally. A major chunk of these users are from emerging markets like India.
"When we started WhatsApp in 2009, people's use of mobile devices looked very different from today. The Apple App Store was only a few months old. About 70 per cent of smartphones sold at the time had operating systems offered by BlackBerry and Nokia," WhatsApp said in a blogpost.
It further said mobile operating systems offered by Google, Apple and Microsoft, which account for 99.5 per cent of sales today, were less than 25 per cent of mobile devices sold at the time.
"As we look ahead to our next seven years, we want to focus our efforts on the mobile platforms the vast majority of people use. So, by the end of 2016, we will be ending support for WhatsApp Messenger on BlackBerry (including BlackBerry 10), Nokia S40, Nokia Symbian S60, Android 2.1, Android 2.2 and Windows Phone 7.1," it said.
The company said this is a "tough decision" but the "right one" in order to give people better ways to keep in touch.
In February 2014, WhatsApp was acquired by social networking giant Facebook, its biggest buyout till date, for a whopping USD 19 billion.
The platform witnesses 42 billion messages, 1.6 billion photos and 250 million videos being shared everyday. Also, there are one billion groups on WhatsApp.
Earlier, WhatsApp had said its service has seen a strong uptake, specially across developing nations such as Brazil, India and Russia.
WhatsApp competes with messaging apps like LINE, Viber and Hike in India.