China said Wednesday it plans to use a refurbished aircraft carrier for research, experiment and training.

Defense Ministry spokesman Geng Yansheng told reporters Wednesday that work was under way on refitting an old carrier, a reference to the Varyag, whose stripped-down hull was towed from Ukraine in 1998.

Defense Ministry spokesman Geng Yansheng answers questions during a news conference in Beijing, July 27, 2011.[Photo/Xinhua]

Geng declined to reveal the specific time for a trial voyage of what will be the country's first aircraft carrier, saying the timing depends on the progress of the whole project.

The development of an aircraft carrier does not signal that China will change its defensive defense policy, Geng told the press conference.

"China's research on the development of an aircraft carrier is to promote the capabilities in maintaining peace and safeguarding the national security," he said.

The training of carrier-borne aircraft pilots is underway, Geng said, adding that that mainly relies on China's own efforts.

He rejected speculation that the timing of revealing the aircraft information is related to the disputes on the South China Sea.

"Building a carrier is a complex project which takes a lot of time. It's appropriate that we disclosed some of the information at this time."