A Chinese fighter jet swerved in front of a U.S. reconnaissance aircraft over the South China Sea in an “unnecessarily aggressive maneuver,” the Pentagon said, part of what a senior American official described as a pattern of more confrontational behavior in the region.

The pilot of the J-16 fighter flew “directly in front of the nose of the RC-135, forcing the U.S. aircraft to fly through its wake turbulence,” according to a statement from the U.S. Indo-Pacific Command. “The RC-135 was conducting safe and routine operations over the South China Sea in international airspace, in accordance with international law.”

A video of the May 26 encounter filmed from the cockpit of the American aircraft shows the Chinese warplane — against a clear blue sky — banking from right to left across the path of the U.S. jet, which visibly shakes as a result. The Chinese jet was about 400 feet from the U.S. plane, officials said.

Liu Pengyu, spokesperson for the Chinese embassy in Washington, denounced the U.S.’s frequent “close-in reconnaissance on China,” saying it “poses a serious danger to China’s national security’ He said in a statement that “the US’s provocative and dangerous moves are the root cause of maritime security issues. China urges the U.S. to stop such dangerous provocations, and stop deflecting blame on China.”

The risky interaction comes with the two nuclear-armed powers mired in disagreements, from concerns about each other’s military buildup to the Biden administration’s efforts to curb Beijing’s access to advanced semiconductors.

And while communication continues between agencies, China has rebuffed U.S. requests for senior-level military talks. On Monday, China’s military reaffirmed its rejection of a Pentagon request for the U.S. and Chinese defense chiefs to meet at an upcoming security conference in Singapore.

Defense Secretary Lloyd Austin departed today for Japan, where he’ll meet with government officials before heading to Singapore for the Shangri-La Dialogue.

The U.S. says that military-to-military communication is necessary to prevent accidents or misunderstandings from spiraling into military conflict. China’s embassy in Washington didn’t immediately respond to a request for comment.

A senior U.S. defense official who spoke on condition of anonymity said that the Pentagon doesn’t believe these incidents are the result of Chinese pilots operating independently. Rather, the latest intercept is part of a broader pattern across the South China Sea, the East China Sea, the Taiwan Strait and elsewhere, the official said.

The official said that the timing of the U.S. disclosure wasn’t a response to China’s refusal to meet, saying the delay in revealing the incident stemmed from the declassification process and the need for diplomatic communications.

Such close encounters have happened from time to time in the region, most famously in 2001, when a U.S. Navy EP-3 airplane collided in midair with a Chinese fighter jet. The Chinese jet crashed and its pilot was never found, while the EP-3 landed on China’s Hainan Island, provoking a 10-day standoff after which the 24 American crew members were finally released.

China claims all of the South China Sea as its own territory, an assertion challenged by Vietnam, the Philippines and other countries. Beijing has embarked on an extensive land-reclamation campaign, building landing strips and bases on disputed reefs and atolls.

In its statement, the U.S. repeated its standard formulation that it will keep flying, sailing and operating “wherever international law allows.”

Liu, the Chinese embassy spokesperson, said “China will continue to take necessary measures to resolutely defend its sovereignty and security, and work with regional countries to firmly safeguard peace and stability in the South China Sea.”