China legally intercepted a United States surveillance aircraft over the East China Sea on Sunday, the Defense Ministry announced on Tuesday.

The People's Liberation Army Air Force dispatched two J-10 fighter jets to intercept and dispel the US EP-3 surveillance aircraft after it entered Chinese air space.

"Maneuvers by Chinese pilots were legal, necessary and professional," Ren Guoqiang, a ministry spokesman, said in response to allegations by a US official that Chinese jets had intercepted the US aircraft in an unsafe manner by flying dangerously close to it.

"The US airplane spying in Chinese air space threatened China's national security and undermined Sino-US military relations," Ren said.

"The US should immediately stop such unsafe, unprofessional, unfriendly and dangerous military activities, and take practical steps to maintain positive Sino-US military ties," he added.

On May 24, two Chinese J-10 fighter jets intercepted a US Navy P-3 Orion surveillance aircraft over the South China Sea.

Contact the writer at zhangzhihao@chinadaily.com.cn