The commissioning of the Fujian marks a key milestone in Xi's drive to modernise the Chinese military and project maritime power in the region, against a backdrop of competing territorial claims in the South China Sea and persisting tensions with Taiwan.

The official event took place on Wednesday at a naval port in China's southern island province of Hainan, Xinhua reported.

"After the ceremony, Xi Jinping boarded the Fujian... and learned about the development of the aircraft carrier system combat capabilities and the construction and application of the electromagnetic catapult system," Xinhua said.

Footage of the proceedings released by state broadcaster CCTV showed Xi and other top officials from the country's ruling Communist Party in attendance at the port.

Engaged in a naval rivalry with Washington in the fraught maritime region, China lags behind the United States in overall military prowess, analysts say.

But Beijing has directed billions of dollars into its military in recent years, a trend that has unnerved some governments in East Asia despite China insisting its aims are peaceful.

The navy in particular has seen a massive expansion as leaders seek to grow the country's reach in the Pacific and challenge a US-led alliance.

After conducting sea trials in recent months, the Fujian now joins China's two other carriers in active operation -- the Liaoning and the Shandong.

Analysts have said that the latest carrier boasts more advanced take-off systems, allowing the Chinese air force to deploy jets carrying larger payloads and more fuel.