Japan's biggest mobile carrier NTT Docomo Inc has sold 2.8 million smartphones since April and expects to achieve its sales target of 13 million smartphones in the year to next March, its president told Reuters.

NTT Docomo, which competes with Softbank Corp and KDDI Corp in the domestic market, has seen a sharp decline in users as more switch mobile carriers to buy Apple Inc's iPhone.

"We believe that by offering a varied lineup of smartphones with high levels of services we will be able to compete with our rivals," said Kaoru Kato, who took over as Docomo president in June.

Docomo, which has balked at Apple's condition that if it sells the iPhone it must make up half of the Japanese company's phone sales, developed its own voice-activated interface to rival the U.S. firm's Siri application.

Docomo expects to sell more than a million new generation Galaxy smartphones made by Samsung Electronics Co Ltd this business year in Japan, Kato said.

He also said it has not received any request for additional funding from India's Tata Teleservices, in which it owns a 26 percent stake, and said the firm was likely to generate profit in about the next five to seven years.