China's state media are playing down the military threat posed by the country's new aircraft carrier, suggesting it may be 15 to 20 years before China has a combat-ready carrier.

In the lead article on its website Thursday, the official Xinhua news agency quotes a Russian military analyst saying the refitted Ukrainian carrier which is undergoing sea trials this week will never be suitable for combat. Ruslan Pukhov, president of the Moscow Strategy and Technologies Analysis Center, says the vessel, called the Varyag, was obsolete even before it was purchased.

The report appears intended to ease fears among China's neighbors that the carrier could become a factor in maritime disputes in the East and South China Seas. Other Chinese media are stressing in their coverage of the launch that the Varyag is to be used for research and training.

Even so, China's military rival Taiwan is featuring what it calls an “aircraft carrier killer” weapon at an arms fair that opened in Taipei Thursday.

The weapon, the Hsiung Feng III, is a Taiwan-built supersonic missile with a range of 130 kilometers. An exhibit at the Taipei Aerospace and Defense Technology Exhibition shows the missile in front of a picture of a burning carrier that bears a striking resemblance to the Varyag.

The United States on Wednesday said Washington would welcome any kind of explanation from China about why it needs an aircraft carrier. A State Department spokeswoman said China's lack of transparency about its military acquisitions and its military budget raises concerns.

The call for greater openness was echoed Thursday by Global Times, a newspaper affiliated with China's ruling Communist Party. The paper described the Varyag as a “test for China's military information disclosure” and said that, while properly protecting military secrets, the government should be frank about its strategic intentions.