China’s first home-built aircraft carrier was officially commissioned by President Xi Jinping on Tuesday as Beijing flexed its military muscles.

The new warship will be called the Shandong and its formal entry into service is a significant milestone in the country’s efforts to build up its naval power.

This drive has been viewed warily by its neighbours and the United States in light of tensions in strategically sensitive areas such as the Taiwan Strait and South China Sea.

The state broadcaster CCTV reported that the ceremony in Sanya, a port in the southern island province of Hainan, was attended by officials from the Southern Theatre Command which oversees the South China Sea.

The ship’s captain will be Lai Yijun, who previously commanded the frigate Lianyungang, while its political commissar will be Pang Jianhong, who served on the destroyer Xian. Both are senior colonels.

Xi inspected an honour guard during the ceremony and met service personnel on board the warship. Other senior officials, including Vice-Premier Liu He, Xi’s chief of staff Ding Xuexiang, China’s top economic planner He Lifeng, and chief of the joint staff department Li Zuocheng, also attended the ceremony.

The vessel, previously known as the Type 001A, passed through the Taiwan Strait to conduct “scientific trials and routine training” and headed to the South China Sea last month.

The ship was expected to be officially commissioned in April, but its trial phase took longer than some military observers had expected, suggesting it had suffered technical problems. The aircraft carrier set out for its first sea trial in May 2018.

By comparison, China’s first aircraft carrier the Liaoning, a refitted Soviet Kuznetsov-class vessel, underwent 13 months of trials before it was commissioned.

The ship is a modified version of the Kuznetsov-class design that features upgraded radar and bridge systems and a ski-jump deck for take-offs.

The ship will be able to carry 36 J-15 fighter jets compared with the Liaoning’s capacity of 24.

Beijing-based naval expert Li Jie said that in total the vessel would be able to carry 40 aircraft, including Z-9 helicopters and KJ-600 early warning planes.

The carrier was constructed by Dalian Shipbuilding Industry in Liaoning province. The company started work on the vessel in November 2013, and laid down the keel for its hull in a dry dock in March 2015.

Li said the commissioning was a “big gift” to mark the 20th anniversary of Macau’s return to Chinese rule. Xi is expected to travel to the casino city on Wednesday for the handover commemorations.

“Beijing chose Sanya [for the commissioning] because the military leadership wanted to highlight the geostrategic importance of China’s second aircraft carrier base,” Li added.

Sanya provides easy access to the South China Sea and is the largest naval complex of its kind in Asia.

Its 700-metre (2,300-foot) carrier dock is able to service multiple carriers simultaneously, and the complex also hosts the Yulin nuclear submarine base.

China’s first carrier base is Qingdao, on the east coast, which is the Liaoning’s home port, and Li said the two bases were able to offer complementary services to the PLA Navy.

Hong Kong-based military expert Song Zhongping said the Shandong was expected to be stationed in Sanya.

He said: “The South China Sea offers ample scope for Chinese aircraft carriers to show their capabilities. It is also the area where the PLA needs to prepare for military struggles.”

He said the two carriers would be under the command of the PLA Navy headquarters, rather than the Northern and Southern Theatre Commands.

But he continued that the Shandong “might be placed under the Southern Theatre Command for joint operations in the event of war in the South China Sea”.

Deploying the new carrier to Sanya was also intended to deter independence-leaning forces in Taiwan, a military source said.

“That’s why the carrier had been sailing through the Taiwan Strait on its way to Sanya last month,” the source, who requested anonymity due to the sensitivity of the topic, said.

Beijing sees Taiwan as a breakaway province that must eventually be reunited with the mainland – by force if necessary.

China’s increasing military power has caused growing unease among the US and its neighbours.

On Monday, Japanese Defence Minister Taro Kono accused China of engaging in unilateral and coercive attempts to alter the status quo in the East and South China seas – where China has territorial disputes with its neighbours.

Kono said Japan was “also concerned about China’s rapid enhancement of its military power without transparency, including its nuclear and missile capabilities”.