China deployed naval and air forces to track and follow a U.S. Navy reconnaissance plane as it transited Tuesday over the Taiwan Strait, the Chinese military said, amid simmering tension between the two superpowers over the fate of the self-ruled island of Taiwan. 

Colonel Cao Jun, a spokesperson for the Chinese army’s Eastern Theater Command Air Force, condemned the U.S. for carrying out the flight and said it had threatened peace and stability in the region. 

The 7th Fleet of the U.S. Navy said Tuesday that a P-8A Poseidon patrol and reconnaissance plane had transited the international airspace over the Taiwan Strait “in accordance with international law,” adding that the plane’s presence showed, “the United States’ commitment to a free and open Indo-Pacific.”

“The United States military flies, sails and operates anywhere international law allows,” said the statement posted to the U.S. Navy website. 

According to the description on the website of manufacturer Boeing, the P-8A Poseidon excels at “anti-submarine warfare; intelligence, surveillance and reconnaissance and search and rescue.” 

Taiwan’s Ministry of Defense said in a statement that it had noted the presence of five Chinese warplanes and seven naval vessels around the island. Four of the Chinese planes entered Taiwanese airspace, and Taiwan deployed “aircraft, Navy vessels, and coastal missile systems in response to the detected activities.”

China has long claimed the democratically governed island of Taiwan as part of its territory, and President Xi Jinping has vowed to bring it back under Beijing’s control after more than seven decades — by force if necessary. 

While the U.S. recognizes Beijing as the sole legal government of China, domestic American law obligates the U.S. to provide Taiwan with military hardware in support of the island’s democratically elected government if it comes under threat. 

Most U.S. administrations have maintained a policy of strategic ambiguity on the extent to which they would support Taiwan in the face of a Chinese invasion, however.

In a September 2022 interview with 60 Minutes, President Biden said the U.S. would intervene militarily to protect Taiwan from China, “if, in fact, there was an unprecedented attack.”

President-elect Donald Trump has largely dodged questions on whether the U.S. would intervene militarily if China were to launch an invasion of Taiwan. In an interview earlier this year, he said Taiwan should pay the U.S. more for helping in its defense. 

China’s military routinely carries out land, navy and air exercises in the Taiwan Strait, the body of water that separates China and Taiwan, which is only about 100 miles across at its narrowest point. Those drills always draw condemnation from both the island’s government in Taipei, and from the White House.