China was an important market but mobile messaging application WhatsApp would not focus on a single country, the company's chief executive and co-founder, Jan Koum, said.
WhatsApp is a cross-platform mobile messaging application that allows users to exchange messages without having to pay SMS charges.
Koum said the application had been very successful in Hong Kong, where 3 million people - or about 45 per cent of the population - were WhatsApp users.
But the mainland could be a difficult market since a WhatsApp-style messaging application for smartphones developed by Tencent, the country's biggest internet company, is set to hit 200 million users this month.
Tencent launched the application, called Weixin, or "WeChat" in English, in January last year and users reached 100 million in March this year.
Tencent accumulated users quickly because it tailored its product to suit the usage habits of Chinese customers. It was also able to market the application to a large existing user pool of users that it had accumulated through its flagship instant messaging service, known as QQ.