A Chinese J-16 fighter flies close to a U.S. RC-135 aircraft in international airspace over the South China Sea on May 26, 2023. [U.S. Navy]

U.S. defense officials are warning of an "alarming increase" in aggressive intercepts from Chinese military aircraft and vessels following a close encounter between a Chinese fighter jet and a U.S. military plane in international airspace over the South China Sea last week.

These "risky" intercepts have the "potential to create an unsafe incident or miscalculation," said two U.S. defense officials who spoke about the incident on the condition of anonymity.

On Tuesday, the U.S. released footage of what it called an "unnecessarily aggressive maneuver" by a Chinese fighter pilot during an intercept of a U.S. Air Force RC-135 aircraft on May 26.

The Chinese pilot "flew directly in front of and within 400 feet (122 meters) of the nose of the RC-135, forcing the U.S. aircraft to fly through its wake turbulence," according to a spokesperson from Indo-Pacific Command, which oversees U.S. military activity in the region.

The spokesperson said the U.S. plane was "conducting safe and routine operations over the South China Sea in international airspace, in accordance with international law" when the intercept occurred.

In a statement, Indo-PACOM called on all countries to use international airspace safely in accordance with international law, adding that the United States "will continue to fly, sail, and operate - safely and responsibly - wherever international law allows."

China blames US

Chinese Foreign Ministry spokeswoman Mao Ning on Wednesday blamed the U.S. for the incident, saying the aircraft was conducting "close-in reconnaissance on China" that was "seriously threatening China's sovereignty and security."

"The U.S. needs to immediately stop such dangerous acts of provocation," Mao said.

An international court ruling in The Hague held that China had no historic title over the South China Sea, but Beijing has ignored the decision.

See VOA's special report: Conflict and Diplomacy on the High Seas

The U.S. frequently conducts operations in and above the South China Sea to challenge the territorial claims of China and others and to promote free passage through international waters that carry half the world's merchant fleet tonnage, worth trillions of dollars each year.

Beijing has claimed every feature in the South China Sea, while Brunei, Malaysia, the Philippines, Taiwan and Vietnam also claim certain islands in the sea as part of their territory.

Beijing declines meeting request

The increased tensions between the U.S. and China come as the Pentagon says Beijing has declined a request by the U.S. for a meeting between their defense chiefs at an annual security forum in Singapore this weekend.

Both defense leaders are slated to attend the annual Shangri-La Dialogue in Singapore, with U.S. Defense Secretary Lloyd Austin speaking on Saturday and his Chinese counterpart, Defense Minister General Li Shangfu, scheduled to speak on Sunday. The annual dialogue is an informal gathering of defense officials and analysts in Singapore that also creates opportunities for side meetings among defense leaders.

Pentagon spokesman Brigadier General Pat Ryder said open lines of communication are important "to ensure that competition does not veer into conflict."

A senior defense official told VOA on Tuesday that since 2021, the PRC has declined or failed to respond to more than a dozen requests from the Department of Defense for key leader engagements, along with multiple requests for standing dialogues and nearly 10 working-level engagements.

"Frankly, it's just the latest in a litany of excuses," the senior defense official said.

China's Foreign Ministry spokesperson also confirmed the two defense leaders would not meet this week, saying Tuesday that the U.S. should "earnestly respect China's sovereignty and security interests and concerns ... and create the necessary atmosphere and conditions for dialogue and communication between the two militaries."

Li, who assumed his current post in March, has been under U.S. sanctions since 2018 over the purchase of combat aircraft and equipment from Russia's main arms exporter, Rosoboronexport.