BEIJING - China's aircraft carrier is underway carrying out scientific testing, a spokesman with the Ministry of National Defense said Wednesday.

Spokesman Yang Yujun said at a press briefing that after attaining objectives during its previous sea trials, the vessel is now carrying out follow-up scientific testing as planned.

Yang said the scientific research and testing will be a long process, and relevant scientific testing and training at sea will continue in the future.

The spokesman denied a report that Russia refused to sell aircraft carrier arrester wires to China, which delayed the aircraft carrier's launch. "The report was entirely groundless," Yang said.

He said China's armed forces adhere to the principle of independent innovation in the development of weapons and equipment.

"The main equipment for our aircraft carrier, including the arrester wires, were developed and converted on our own," he said.

The aircraft carrier was originally built by the former Soviet Union. It was not yet complete when the Soviet Union dissolved in 1991. Ukraine disarmed it and removed its engines before selling it to China.

The vessel, measuring 304.5 meters long and 37 meters wide with a displacement of 58,500 metric tons, has been completely refitted for its new role as a research and training platform for China.

In recent years, the PLA Navy has been modernizing the level of its comprehensive combat power, and it has been actively promoting the holistic transformation of the navy structure, Yang said.

But Yang said it should be stressed that the strategy of China's inshore defense policy has not changed.

He said the Navy undertakes the tasks to defend national security at sea, safeguard sovereignty over territorial waters, and protect maritime rights and interests.

Currently, the United States, the United Kingdom, France, Russia, Spain, Italy, India, Brazil and Thailand operate a total of 21 active-service aircraft carriers.