China has commissioned its first domestically built aircraft carrier on the edge of the disputed South China Sea, in a move observers say is designed to both highlight its growing military clout and give pause to Japan, the United States and Taiwan.

The country's second carrier, named the Shandong, entered service after a "grand commissioning ceremony" in front of 5,000 people and overseen by President Xi Jinping at a naval base in Sanya "at the doorstep of the South China Sea" on China's southern Hainan Island, state media reported.

Footage aired by China Central Television showed Xi boarding the ship to present a flag and certificate, sign the visitors' log and greet sailors. He also inspected aircraft and toured the bridge and flight coordination operations center.