China has sent its only aircraft carrier on a training mission in the South China Sea, where Beijing is engaged in tense territorial disputes with several of its neighbors.
State media say the Liaoning departed Tuesday from its home port in the northern city of Qingdao, accompanied by two destroyers and a missile cruiser.
Chinese naval officials described the carrier's mission as routine, saying it will conduct scientific research, tests and military drills.
It is the Liaoning's first long-term training mission since being commissioned last year, amid concerns about China's growing military capabilities.
Many of China's neighbors accuse it of being more aggressive in recent years in defending its maritime claims in the South China Sea.
Duong Danh Dy, an expert on Vietnam-China relations, told VOA's Vietnamese service that Beijing is trying to exert its control over the disputed water.
"China's latest moves show that the country is more and more assertive in its claims over the South China Sea whenever there is a chance to do so. It's not a surprise move. It's a long-term strategy that China will pursue until the end," said Duong.
In the South China Sea, Beijing has overlapping territorial claims with Vietnam, the Philippines, Malaysia and Brunei.
China bought the vessel as an unfinished Soviet aircraft carrier from Ukraine in 1998. After spending years refurbishing it, the Liaoning entered service last September.
The carrier's capabilities are seen as limited, and China has described its role as "experimental." But the carrier is said to represent wider Chinese naval ambitions.