Chinese jets intercept U.S. radiation-sniffing plane, U.S. says

The US WC-135 Constant Phoenix aircraft was carrying out a routine mission at the time and was operating in accordance with worldwide law. They said the incident was being run through the "appropriate diplomatic channels" to address the actions of the Chinese pilots.

"Distances always have a bearing on how we characterise interactions", Hodge said.

The US Air Force has slammed Chinese fighter pilots for an unprofessional manoeuvre involving a jet flying upside down to intercept an American plane.

Chinese foreign ministry spokeswoman Hua Chunying declined to comment on the specific incident, referring questions to the defense ministry which not yet commented.

"So we hope the USA side can respect China's reasonable national security concerns". In the second case, a Chinese J-10 fighter came within 100 feet of a U.S. Navy RC-135 reconnaissance aircraft.

Such incidents have occurred occasionally over and within the South China Sea, which China claims virtually in its entirety.

The U.S. opposes China's territorial claims in the region, and routinely asserts its right to fly or sail in areas it considers global seas or airspace.

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The "nuclear sniffer" plane was sent to monitor radiation levels in the area, in accordance with global law, and regularly completes missions in North East Asia, according to Air Force spokesperson Lieutenant Colonel Lori Hodge.

She said the United States aircraft had been carrying out a routine mission at the time and was following global law.

It is noted that this American plane detects radioactive isotopes in the atmosphere, which are signs of nuclear testing.

China's Defense Ministry however, reportedly said the USA was just "hyping up the issue".

This undated photo provided by the U.S. Air Force shows the WC-135W Constant Phoenix aircraft during flight.

In February there was what U.S. Officials call an "unsafe close encounter" between a U.S. Navy P-3 Orion and a Chinese surveillance aircraft over the South China Sea.

  • Adam Floyd