Beijing: China's ambitious new long range ballistic missile with a range of 2,700 km dubbed as carrier-killer is undergoing tests, a top military official has said.

Chen Bingde, chief of the People's Liberation Army (PLA) General Staff acknowledged that China is developing Dongfeng-21D with an ability to strike moving targets -including aircraft carriers - at sea.

 "The missile is still undergoing experimental testing and will be used as a defensive weapon when it is successfully developed, not an offensive one," Chen was quoted as saying during his rare interaction with media coinciding after talks with Mike Mullen, chairman of the US Joint Chiefs of Staff on Monday.

"It is a high-tech weapon and we face many difficulties in getting funding, advanced technologies and high-quality personnel, which are all underlying reasons why it is hard to develop this," he said about the ballistic missile which has a maximum range of 2,700 kilometres.

The development of the missile caused considerable in US as it was believed to have been developed to target aircraft carriers.

Chen also said the first Chinese aircraft carrier, Varyag a refurbished version of an old Ukrainian ship will be used for research.

"I have nothing more to say about Chinese aircraft carriers, since prominent media outlets have already reported on them so much. Our American friends all know that China bought an old aircraft carrier, the Varyag, from Ukraine. It's very valuable for us to research these things this way, "he said.

Meanwhile Chinese Defence Ministry has dismissed reports that PLA plans to develop two fleets of aircraft carriers. The news report is groundless and extremely irresponsible.

Commenting on China's aircraft carrier, Mullen said while "great symbolism" is associated with China's first aircraft carrier, "sometimes matching the actual capability versus the symbolism, there can be a gap there".

The 67,500-ton Varyag is considerably smaller than the Japan-based US carrier George Washington, which has a displacement of more than 100,000 tons.

The Varyag was bought from Ukraine for USD 20 million in 1998. According to reports, it has been undergoing refitting work at a shipyard in the north eastern coastal city of Dalian since 2005.