China announced more military drills around Taiwan as the self-governing island’s president met with members of a new U.S. congressional delegation on Monday, threatening to renew tensions between Beijing and Washington just days after a similar visit by U.S. House Speaker Nancy Pelosi angered China.

Pelosi was the highest-level member of the U.S. government to visit Taiwan in 25 years, and her trip prompted nearly two weeks of threatening military exercises by China, which claims the island as its own. Beijing fired missiles over the island and into the Taiwan Strait and sent warplanes and navy ships across the waterway’s midline, which has long been a buffer between the sides that split amid civil war in 1949.

China accuses the U.S. of encouraging the island’s independence through the sale of weapons and engagement between U.S. politicians and the island’s government. Washington says it does not support independence, has no formal diplomatic ties with the island and maintains that the two sides should settle their dispute peacefully — but it is legally bound to ensure the island can defend itself against any attack.

“China will take resolute and strong measures to defend national sovereignty and territorial integrity,” Chinese Foreign Ministry spokesperson Wang Wenbin said at a daily briefing Monday, after Beijing announced new drills in the seas and skies surrounding Taiwan. “A handful of U.S. politicians, in collusion with the separatist forces of Taiwan independence, are trying to challenge the one-China principle, which is out of their depth and doomed to failure.”

The new exercises were intended to be “resolute response and solemn deterrent against collusion and provocation between the U.S. and Taiwan,” the Defense Ministry said earlier.

It was not clear if the new drills had already started since the ministry gave no details about where and when they would be conducted, in contrast to previous rounds.

The U.S. lawmakers, led by Democratic Sen. Ed Markey of Massachusetts, met with Taiwanese President Tsai Ing-wen, Foreign Minister Joseph Wu and legislators, according to the American Institute in Taiwan, Washington’s de-facto embassy on the island. The delegation “had an opportunity to exchange views with Taiwan counterparts on a wide range of issues of importance to both the United States and Taiwan,” the institute said in a statement.

China says it wants to use peaceful means to bring Taiwan under its control, but its recent saber rattling has emphasized its threat to take the island by military force. The earlier drills appeared to be a rehearsal of a blockade or attack on Taiwan that would force the cancellation of commercial flights and disrupt shipping to Taiwan’s main ports as well as cargo passing through the Taiwan Strait, one of the world’s busiest shipping lanes.

The exercises prompted Taiwan to put its military on alert, but were met largely with defiance or apathy among the public used to living in China’s shadow.

The American “visit at this time is of great significance, because the Chinese military exercise is (intended) to deter U.S. congressmen from visiting Taiwan,” Lo Chih-cheng, the chair of the Taiwan legislature’s Foreign and National Defense Committee, said after meeting with the U.S. lawmakers.

“Their visit this time proves that China cannot stop politicians from any country to visit Taiwan, and it also conveys an important message that the American people stand with the Taiwanese people,” Lo said.

A senior White House official on Asia policy said last week that China had used Pelosi’s visit as a pretext to launch an intensified pressure campaign against Taiwan, jeopardizing peace and stability across the Taiwan Strait and in the broader region.

“China has overreacted, and its actions continue to be provocative, destabilizing, and unprecedented,” Kurt Campbell, a deputy assistant to U.S. President Joe Biden, said on a call with reporters on Friday.

Campbell said the U.S. would send warships and planes through the Taiwan Strait in the next few weeks and is developing a roadmap for trade talks with Taiwan that he said the U.S. intends to announce in the coming days.

Beyond the geopolitical risks of rising tensions between two world powers, an extended crisis in the Taiwan Strait 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.

This week’s five-member congressional delegation planned to meet with both government and private sector representatives. Investment in Taiwan’s crucial semiconductor industry and reducing tensions in the Taiwan Strait were expected to be key topics of discussion.

The other members of the delegation are Republican Rep. Aumua Amata Coleman Radewagen, a delegate from American Samoa, and Democrats John Garamendi and Alan Lowenthal from California and Don Beyer from Virginia.

AP