PINGTUNG, Taiwan (AP) – Taiwan warned Tuesday that Chinese military drills are not just a rehearsal for an invasion of the self-governing island but also reflect ambitions to control large swaths of the western Pacific, as Taipei conducted its own exercises to underscore it is ready to defend itself.

Angered by U.S. House Speaker Nancy Pelosi’s recent visit to Taiwan, China has sent military ships and planes across the midline that separates the two sides in the Taiwan Strait and launched missiles into waters surrounding the island. The drills, which began Thursday, have disrupted flights and shipping in one of the busiest zones for global trade.

Ignoring calls to calm tensions, Beijing instead extended the exercises without announcing when they will end.

Taiwanese Foreign Minister Joseph Wu said that beyond aiming to annex the island democracy, which split with the mainland amid civil war in 1949, China wants to establish its dominance in the western Pacific. That would include controlling of the East and South China Seas via the Taiwan Strait and imposing a blockade to prevent the U.S. and its allies from aiding Taiwan in the event of an attack, he told a news conference in Taipei.

The exercises show China’s “geostrategic ambition beyond Taiwan,” which Beijing claims as its own territory, Mr. Wu said.

Mr. Wu’s assessment of China’s maneuvers was grimmer than that of other observers but echoed widespread concerns that Beijing is seeking to expand its influence in the Pacific, where the U.S. has military bases and extensive treaty partnerships.

China has said its drills were prompted by Mrs. Pelosi’s visit, but Mr. Wu said Beijing was using her trip as a pretext for intimidating moves long in the works. China also banned some Taiwanese food imports after the visit and cut off dialogue with the U.S. on a range of issues from military contacts to combating transnational crime and climate change.

Through its maneuvers, China has pushed closer to Taiwan’s borders and may be seeking to establish a new normal in which it could eventually control access to the island’s ports and airspace. But that would likely elicit a strong response from the military on the island, whose people strongly favor the status quo of de-facto independence.

The U.S., Taipei’s main backer, has also shown itself to be willing to face down Beijing’s threats. Washington has no formal diplomatic ties with Taiwan in deference to Beijing, but is legally bound to ensure the island can defend itself and to treat all threats against it as matters of grave concern.

That leaves open the question of whether Washington would dispatch forces if China attacked Taiwan. U.S. President Joe Biden has said repeatedly the U.S. is bound to do so—but staff members have quickly walked back those comments.

Beyond the geopolitical risks, an extended crisis in the Taiwan Strait, a significant thoroughfare for global trade, could have major implications for international supply chains at a time when the world is already facing disruptions and uncertainty in the wake of the coronavirus pandemic and the war in Ukraine. In particular, Taiwan is a crucial provider of computer chips for the global economy, including China’s high-tech sectors.

In response to the drills, Taiwan has put its forces on alert, but has so far refrained from taking active counter measures.

Taiwan, once a Japanese colony, had only loose connections to imperial China and then split with the mainland in 1949. Despite never having governed the island, China’s ruling Communist Party regards it as its own territory and has sought to isolate it diplomatically and economically in addition to ratcheting up military threats.