The vessel, which is equipped with advanced electromagnetic catapults for launching fighter jets, left Shanghai's Jiangnan Shipyard at about 8 a.m., Chinese state news agency Xinhua reported. The goal, it said, is to test the carrier's propulsion and electrical systems.
The maneuvers come a day after Chinese ships fired water cannons at Philippine vessels in the South China Sea. The carrier's departure also closely follows a visit by a group of Japanese lawmakers, including former Defense Minister Tomomi Inada, to the Senkaku Islands in the East China Sea over the weekend. Japan administers the islets and does not acknowledge any disputes over their sovereignty, but China -- which claims the islands and calls them Diaoyu -- lodged a diplomatic protest over the parliamentarians' tour.
On Monday, the Shanghai Maritime Safety Administration declared an area of the East China Sea off limits to traffic from May 1 to 9, due to scheduled "military activities."
Su Hao, a political commentator in China, suggested the timing of this notice and the aircraft carrier trials were not a coincidence. Characterizing the People's Liberation Army (PLA) naval operations as military activity, rather than training, could allow "more targeted" countermeasures against Japan, Su wrote in a blog post.
The Fujian, scheduled to be commissioned in 2025, promises to enhance China's ability to project power. Technologically, the PLA Navy's third carrier is a leap forward compared with its predecessors, the Liaoning, which was originally built for the Soviet Navy, and the domestically built Shandong, which borrows the old "ski jump" design.
The new carrier is "much more capable" than the Liaoning and Shandong, said Collin Koh, senior fellow at the S. Rajaratnam School of International Studies in Singapore.
The introduction of the electromagnetic catapults will allow China to overcome the takeoff and landing limitations of the ski-jump decks. It should also enable each jet to carry more bombs and missiles, allowing China to "generate more combat power," Koh said. He explained that the catapult system "allows for the aircraft to have maximum payload, and they could still be launched into the air in a safer manner."
One question mark, he said, is how effective the system will be given that electromagnetic catapults are "actually very power consuming." Koh said it depends on China's capabilities to use available power efficiently.
The U.S. has also introduced electromagnetic catapults on its carrier USS Gerald R. Ford, replacing traditional steam catapults.
According to Hong Kong media, the PLA Navy intends to have a fleet of six aircraft carriers by 2035. Adm. Yuan Huazhi, the navy's political commissar, told a newspaper that China is currently building its fourth carrier, while hurrying to add guided missile destroyers to protect the carriers.
Koh said China gained "quite a lot of insights" in the process of converting the Liaoning for its navy, and that its approach to carriers was still evolving. "I don't think the Fujian is a definitely final design," he said. "It might be the baseline design for the Chinese carrier program going forward," with subsequent units becoming "more advanced."
Japan, which is ramping up its own defense spending alongside the rest of East Asia, is warily watching China's growing maritime presence.
A report issued by Japan's Ministry of Defense in March said that China seems to be attempting "to make its activities routine in the Sea of Japan and Pacific Ocean in addition to the sea area around the Senkaku Islands." The PLA, it said, has "rapidly expanded and intensified [their] activities in the maritime and aerial domains."
While China tests the waters with Japan, it is also asserting itself with frequent incursions around Taiwan and bold moves in the South China Sea.
On Wednesday, the head of Taiwan's National Security Bureau, Tsai Ming-yen, said Taipei will be on guard for Chinese military drills from June through November, following the May 20 inauguration of President-elect Lai Ching-te. "Whether the Chinese Communists use this hot season as an excuse to carry out some military drills to further pressure Taiwan is a key point the National Security Bureau is focusing on," he told the media.
On Tuesday, the Philippine Coast Guard announced that China Coast Guard ships and maritime militia vessels had conducted "dangerous maneuvers and obstruction" against Philippine vessels near Scarborough Shoal in the South China Sea. Beijing's boats fired "their jet stream water cannons, targeting the PCG vessel from both sides, resulting in damage to the railing and canopy," according to the Philippine statement.
A spokesperson for China's Foreign Ministry dismissed the accusations, saying that the Philippine vessels had "intruded without China's permission," and that the coast guard "took necessary measures to drive them away."
In July 2016, the international Court of Arbitration in The Hague ruled against China's territorial claims in the South China Sea, based on the United Nations Convention on the Law of the Sea. But China continues to press its claims to most of the waterway.
Jay Tarriela, a Philippine Coast Guard spokesperson, wrote on X that Tuesday's incident "highlights China's lack of concern for regional peace and stability."
The China challenge, however, has brought Indo-Pacific partners closer together. The U.S., Japan and the Philippines last month held their first trilateral leaders' summit in Washington, promising "many more" to come. On Thursday, the three countries' defense ministers are due to convene in Hawaii for follow-up security talks, with Australia also included.