Washington DC - President Donald Trump's administration directly criticized China for aiming its radars at and jamming a Japanese military aircraft during a training exercise last week.

Condemnation of Beijing came from the US State Department just days after an incident in which Chinese J-15 fighter jets reportedly locked in on a Japanese Air Self-Defense Force plane.

The incident was considered dangerous because radar locking indicated to the Japanese plane that it was under attack, forcing it to take evasive maneuvers.

Both Tokyo and Beijing have relayed varying accounts of what happened, with China claiming that the Japanese plane had disturbed training exercises nearby.

China Taiwan warns China has deployed a "significant" number of warships for "military operations"

"China's actions are not conducive to regional peace and stability," a State Department spokesperson said on Tuesday in comments cited by Reuters.

"The US-Japan Alliance is stronger and more united than ever. Our commitment to our ally Japan is unwavering, and we are in close contact on this and other issues."

Japan expressed appreciation for the US' support, the country's Chief Cabinet Secretary Minoru Kihara saying that it "demonstrates the strong US-Japan alliance."

The incident comes amid escalating tensions between the two countries, spurred on by Japanese Prime Minister Sanae Takaichi's threats to respond militarily if Beijing invades Taiwan.

Chinese Foreign Ministry Spokesperson Guo Jiakun on Wednesday used a regular press conference to slam the US for taking Japan's side.

"It was the Japanese side who first deliberately made harassment and then spread disinformation," Guo said. "The Japanese side is the provocateur responsible for orchestrating this political stunt."

"We hope the international community can be clear-eyed and not be deceived by the Japanese side. Japan's allies in particular need to stay on high alert and not to be misguided by the Japanese side."