China launched two days of military drills surrounding Taiwan on Thursday in what it called a “strong punishment” to its opponents on the self-governing island, after Taiwan’s new president pledged to defend its sovereignty.

The drills were the first substantive response by China to the swearing-in of President Lai Ching-te, whom Beijing dislikes, in Taipei on Monday. Mr. Lai’s political party asserts Taiwan’s separate status from China, and in a high-profile inaugural speech, he vowed to keep Taiwan’s democracy safe from Chinese pressure.

China, which claims Taiwan as its territory, had mainly responded to Mr. Lai’s speech with sharply worded criticism. But it escalated its response Thursday by announcing that it was conducting sea and air exercises that would encircle Taiwan and draw close to the Taiwanese islands of Kinmen, Matsu, Wuqiu and Dongyin in the Taiwan Strait.

From the start of the exercises until the afternoon, 15 Chinese navy vessels, 16 Chinese coast guard vessels and 42 Chinese military aircraft were detected around Taiwan’s main island and smaller outlying islands, according to Taiwan’s Defense Ministry. Officials at a briefing in Taipei said that so far none of the Chinese aircraft and vessels had entered Taiwan’s territorial waters.

“We must express our condemnation for this behavior that damages regional peace and stability,” Sun Li-fang, a spokesman for the Taiwanese ministry, told the briefing.

The last time China held a major drill in multiple locations around Taiwan was in April 2023, after Kevin McCarthy, then the speaker of the House of Representatives, met with the president of Taiwan at the time, Tsai Ing-wen. Beijing opposes such exchanges with the island’s leaders.