China stages largest show of force in decades after US visit by Taiwan’s Lai

China’s military didn’t announce the start of any drills. But Taiwanese authorities said Tuesday they were seeing “major elements of a military drill" over a vast expanse of air and sea near Taiwan.

The maneuvers are an apparent expression of Beijing’s anger over President Lai Ching-te’s recent visit to Hawaii and the U.S. territory of Guam as part of his first international tour as president.

The Chinese Communist government considers Taiwan part of China, despite having never ruled there, and has pledged to take it by force if necessary. China vehemently opposes contact between Taiwan and American officials.

Before Lai’s departure, Beijing vowed to “resolutely crush any ‘Taiwan independence’ separatists," a label Beijing applies to Lai.

The maneuvers are “a significant security challenge to us," said Maj. Gen. Sun Li-fang, the spokesman for Taiwan’s Defense Ministry. “The threats aren’t just aimed at Taiwan. They’re also a threat to other countries in the region."

China has deployed nearly 60 naval ships and almost 30 other coast guard vessels, a senior Taiwanese official said. It deployed forces from its northern, southern and eastern theater commands, in the waters spanning from the East Sea to South China Sea.

A senior Taiwanese security official said the Chinese military appeared to be testing its capacity to dominate the so-called first-island chain, which stretches from north of Japan to Borneo in the south and would be a key focus in any regional conflict.

The Chinese operations are potentially “more than just about Taiwan," said Drew Thompson, former Pentagon official responsible for China and Taiwan, now a senior fellow at Singapore’s S. Rajaratnam School of International Studies. China is “simultaneously using military coercion to intimidate other countries in the Western Pacific, including Japan, maybe Korea, Philippines, and then maybe indirectly other countries in the South China Sea."

Taiwan’s Defense Ministry on Tuesday reported 47 warplanes and 21 Chinese vessels near the island for the past 24 hours. Taiwanese military officials said the large-scale maritime presence is not only China training to enforce a blockade on Taiwan, but also an effort to implement a strategy to prevent other militaries from coming to Taiwan’s aid.

“To our east, there’s a wall of PLA Navy forces, and right next to our air defense identification zone, there’s another one," Taiwan intelligence officer Lt. Gen. Hsieh Jih-sheng told reporters Tuesday. With ships to the west and east of Taiwan, “they’re sending us a pretty clear message: to turn the Taiwan Strait into their internal waters," he added

The exercises were a pointed reminder of the potential for a conflict in the region that could involve the U.S., Taiwan’s staunchest ally.

The U.S. has traditionally maintained so-called strategic ambiguity as to whether it would intervene to help Taiwan in a conflict with China. While President Biden has said repeatedly the U.S. would intervene in a conflict, his advisers have walked back the remark, saying there had been no change to American policy.

Donald Trump said in an interview with NBC News broadcast Sunday that he would not say whether he would send U.S. forces to defend Taiwan from a Chinese invasion.

“I’d prefer that they don’t do it," the president-elect said. “I have a very good relationship with President Xi. We have been communicating with each other." Trump added that Taiwan wasn’t discussed in a recent exchange with the Chinese leader.

On Sunday, China said that portions of the airspace along its coast were reserved until midday Wednesday, which would allow for restrictions on air travel. The areas include parts of the Strait of Taiwan near Fujian province and coastal regions of Zhejiang province and Shanghai. At least seven Chinese coast guard vessels were also reported near Taiwan as of Monday, including one of the world’s longest coast guard patrol ships, the Haijing 2901.

In response to recent Chinese military activities, Taiwan’s military said it had launched a war-preparedness drill, which includes air-defense and anti-landing operations. Meanwhile, the island’s coast guard said it immediately deployed patrols to match the Chinese coast guard vessels.

Last week, Lai made several private calls with both Democratic and Republican heavyweights, including former House Speaker Nancy Pelosi, during his Hawaii visit. Pelosi’s 2022 visit to Taiwan drew outrage from China.

He also held phone and video calls with members of Congress, including House Speaker Mike Johnson (R., La.), House Minority Leader Hakeem Jeffries (D., NY) and Sen. Roger Wicker (R., Miss.), the highest-ranking Republican on the Senate Armed Services Committee.

“I hope China will open its arms instead of clenching its fists. No matter how many military exercises, warships or warplanes are used to intimidate neighboring countries, it won’t earn anyone’s respect," Lai told reporters in Palau before concluding his trip on Friday.

China previously launched drills in October following a speech by Lai and again in May, after his inauguration.

The latest Chinese maneuvers came days after Taiwanese officials said Russian navy ships had sailed past the island. The four Russian ships—three Steregushchiy-class corvettes and a fuel-supply ship—sailed near 24 nautical miles of Taiwan, in what appeared to be drills coordinated with Chinese warships.

“Russia and China have pledged to support each other’s core interests," said Jacob Stokes, who served on then-Vice President Biden’s national-security staff and is a senior fellow at the Center for a New American Security, a Washington think tank. “So, China supports Russia in Ukraine, and Russian exercises near Taiwan are part of Russia reciprocating by helping to pressure Taiwan."

China and Russia carry out regular military drills together. In December 2022 they conducted exercises in the East China Sea, just to the north of Taiwan, that analysts said were likely meant to display the sort of quarantine and blockade capabilities that might be used in a conflict over Taiwan.

Write to Joyu Wang at joyu.wang@wsj.com and Austin Ramzy at austin.ramzy@wsj.com