TAIPEI, Taiwan (AP) -- China conducted military drills around Taiwan for a second day Wednesday, focusing on the Taiwan Strait -- a crucial conduit for international trade separating the self-governing island democracy from China.

The Strait Thunder-2025A drills were held in the middle and southern areas of the strait, a People's Liberation Army spokesperson said.

Taiwan's military said that it was closely monitoring the drills, but there was nothing unusual on the island of 23 million people that China claims as its own territory.

The latest exercises "focus on subjects of identification and verification, warning and expulsion, and interception and detention so as to test the troops' capabilities of area regulation and control, joint blockade and control, and precision strikes on key targets," Eastern Theater Command spokesperson Shi Yi was quoted as saying on the Chinese Defense Ministry's Weibo social media account.

Taiwan reported that 76 military aircraft and 19 naval or government ships had entered waters and airspace near the island, with 37 of the planes crossing the center line in the 160-kilometer (110-mille) wide Taiwan Strait that forms an unofficial border, but which China refuses to acknowledge.

China's Shandong aircraft carrier group also entered into Taiwan's air defense identification zone, a self-defined area tracked by the military.

Shi said the Shandong joined in on Wednesday's drills in coordination with naval and air units in the Pacific Ocean east of Taiwan. The exercises focused on seizing air superiority in the area and evaluating forces' ability to integrate operations "inside and outside the island chain," Shi said, in a reference to the arc of islands closest to China including the Philippines, Taiwan, Okinawa and southern Japan.

Beijing sends warplanes and naval vessels toward the island on a daily basis, and it has stepped up the scope and scale of these exercises in recent years. Taiwanese officials have recently warned that China could launch a sneak attack under the guise of military exercises.

Any conflict could draw in the U.S., which maintains a series of alliances in the region, provides Taiwan with high-tech arms and is legally bound to respond to threats to the island.

"Once again, China's aggressive military activities and rhetoric toward Taiwan only serve to exacerbate tensions and put the region's security and the world's prosperity at risk," U.S. State Department spokesperson Tammy Bruce said.

"In the face of China's intimidation tactics and destabilizing behavior, the United States' enduring commitment to our allies and partners, including Taiwan, continues," Bruce said in a statement.

Taiwan has set up a central response group to monitor the latest exercises, according to Taiwanese Defense Minister Wellington Koo.

China's Taiwan Affairs Office said that the exercises were directed at Lai Ching-te, Taiwan's strongly pro-independence president. Polling shows the overwhelming majority of the island's residents reject the possibility of Chinese rule and back their current state of Taiwan independence.

Taiwan and China split amid civil war 76 years ago, but tensions have risen since 2016, when China cut off almost all contacts with Taipei.