File photo of China's Foreign Minister spokesperson Hong Lei. [Photo: fmprc.gov.cn]

China has rejected Vietnam's protests of test flights to a newly built airport on a reef in the South China Sea.

The move comes after Vietnam's Civil Aviation authorities sent protest letters to Beijing and to the United Nation's International Civil Aviation Organization.

China's Foreign Ministry spokesperson Hong Lei:

"We should reiterate that China has indisputable sovereignty over the Nansha Islands and their adjacent waters. China's test flights to the newly built airport on Yongshu Jiao fall totally within China's sovereignty. The accusations that China's test flights 'threaten the safety of all flights in the region' are entirely groundless."

According to the Vietnamese side, the test flights conducted by China violate international laws as the country didn't notify Vietnam in advance.

In response, Hong Lei says China's Civil Aviation authority notified Vietnam, providing detailed technical information of the test flights on December 28 and 30 last year, including flight plans and air routes.

Hong says the test flights showed that the airport can serve humanitarian purposes:

"The inspection results show that the new airport accords with the standards of civil aviation and has the ability to ensure civilian airplanes' safety. Thus it can help support personal exchanges in the region and lift public service capabilities, including maritime rescues in the South China Sea.

China on Wednesday conducted two test flights landing on and taking off from its newly built airport on Yongshu Jiao in the South China Sea.