The maiden sea trial of China's first aircraft carrier "has attained the anticipated objectives", a spokesman from the Defense Ministry said on Wednesday.

China's first aircraft carrier, the 300-meter-long Varyag, has steamed onto the world stage for sea trials. China becomes the last of the five permanent members of the United Nations Security Council to deploy an aircraft carrier.

Ministry spokesperson Yang Yujun said at a regular press briefing that the carrier has returned to the shipyard where refurbishing and testing will continue, but did not elaborate on the "anticipated objectives."

The vessel, former Soviet aircraft carrier Varyag, has been totally refitted for its new role as a research and training platform in China. The vessel departed from a port in Dalian, a city in northeast China's Liaoning Province on Aug. 10.

China's People's Liberation Army Navy's (PLA Navy) inshore defense strategy and the defensive nature of the country's national defense policy will not change despite the country's development of advanced weaponry, Yang said at the news briefing.

The building of an aircraft carrier is a long and complex project. In the building process, there will be a series of scientific research experiments and training exercises, and such activities are "routine and normal," Yang said.

Follow-up work on the aircraft carrier will be fixed based on training and scientific research needs, according to the spokesperson.

The vessel is an Admiral Kuznetsov class aircraft carrier which measures 304.5 meters long and 37 meters wide, with a displacement of 58,500 metric tons.

The Soviet Union began construction on the vessel in 1985. Construction of the ship stopped in 1992, leaving the vessel structurally complete, but lacking electronics.

After the Soviet Union disbanded in 1991, Ukraine took control of the ship. The ship went unused, maintained, and, eventually, stripped.

Since March 2002, the vessel has quietly berthed in the Port of Dalian with its hull and deck painted PLA Navy grey.

On July 27, the Ministry confirmed China's aircraft carrier program, emphasizing that the carrier was intended solely for "scientific research, experiments and training."

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

Japan's Maritime Self-Defense Force currently has two 18,000-metric ton Hyuga-class helicopter carriers, although the warships are classified by Japan as "helicopter destroyers."

Once the still-unnamed carrier is delivered to the PLA Navy, China will be the last among the permanent members of the U.N. Security Council to possess an aircraft carrier.