China's most advanced aircraft carrier, the Fujian, has entered service days after a grand commissioning ceremony overseen by Chinese leader Xi Jinping, state media reported.

The Fujian, the country's third aircraft carrier, is equipped with electromagnetic catapults which will allow planes to be launched at higher speeds.

Its entry into active duty marked a significant step forward for Beijing, which now has the world's largest navy in terms of sheer number of ships.

China has been expanding its navy at breakneck speed under Xi, putting pressure on the United States and its allies to keep up.

The Fujian can launch three different types of aircraft with its electromagnetic catapult and flat flight deck, according to state media.

The domestically-built vessel can carry planes with heavier weapons and fuel loads so they can strike enemy targets from a greater distance, making it more powerful than China's first two carriers, the Liaoning and the Shandong.

State media hailed the Fujian as a major milestone in the development of China's navy.

The US is the only other country in the world to have an aircraft carrier with the same electromagnetic catapult system as Fujian.

The Fujian's commissioning ceremony was held in southern Hainan province on Wednesday, during which Xi toured the ship's deck to learn more about its performance at sea.

Reports suggested Xi personally decided to adopt electromagnetic catapult technology, indicating a commitment to modernize China's naval fleet.

During the ceremony, Xi also spoke to sailors who lined up along the flight deck, saluting and shouting in unison: Follow the party's command, fight to win, and uphold fine conduct!