China set to declare ADIZ over South China Sea: Report

China is set to declare an air defence identification zone (ADIZ) over the disputed South China Sea to counter US military's provocative moves in the strategic waterways, according to a Hong Kong-based media, South China Morning Post report.

"If the US military keeps making provocative moves to challenge China's sovereignty in the region, it will give Beijing a good opportunity to declare an ADIZ in the South China Sea," the report quoted sources in the People's Liberation Army (PLA) as saying.

The timing of the declaration of the ADIZ would depend on security conditions in the region, particularly the US military presence and diplomatic ties with neighbouring countries, it quoted another Chinese official as saying.

The development comes two years after China announced an ADIZ in the East China Sea. ADIZ requires all incoming aircraft, including civilian planes, to register with Chinese authority to fly in the air routes.

The report came ahead of next week's US-China annual Strategic and Economic Dialogue here on June 6-7 in which US Secretary of State John Kerry would take part.

Officially China maintains that it is the right of a sovereign state to designate an ADIZ in its waters.

"Regarding when to declare such a zone, it will depend on whether China is facing security threats from the air, and what the level of the air safety threat is," the official stated to the Hong-Kong based media.

China, which has built airfields and placed weapons systems on the man-made islands in the Sea, claims almost all of the South China Sea. Vietnam, the Philippines, Malaysia, Brunei and Taiwan have rival claims.

The rival claimants have been fretting over what they see as China's expansionism, as it rushes to exert sovereignty over the vital waterway — a major global shipping route believed to have large oil and gas reserves — and through which about $ 5 trillion in trade passes each year.

The US has been wading into the dispute, pressing its naval ships and aircraft to assert the freedom of navigation in the disputed region. Its moves in recent months have led to angry protests from China.

US military defend its maneuvers in the region and say they will continue to exercise freedom of navigation. In the past seven months, US warships have sailed three times close to one of the artificial islands and challenged the claims.

In response, China has deployed fighter jets and ships to track and warn off US ships.