"We would consider such an ADIZ over portions of the South China Sea as a provocative and unilateral act that would raise tensions and call into serious question China's commitment to diplomatically managing territorial disputes in the South China Sea," State Department Spokesperson Marie Harf told reporters yesterday.
"We've made very clear that parties must refrain from announcing an ADIZ or any other administrative regulation restraining activity of others in disputed territories. We would of course urge China not to do so," she said, amidst reports in the Japanese media that China is preparing to declare ADIZ over portions of the South China Sea.
China last year unilaterally declared an Air Defence Identification Zone in the East China Sea, asking foreign planes to identify themselves.
China claims almost all of South China Sea as its own which is strongly contested by Philippines, Vietnam, Malaysia and Brunei.
"I am not aware that the Chinese have established a new ADIZ in South China Sea. If they were to, our position on ADIZ is very clear. I do not think our position is going to change. We do not recognise the one that was recently established," Pentagon spokesman Army Col
Steven Warren told reporters.
Meanwhile, Republican Senator Marco Rubio, the Ranking Member of the Subcommittee on East Asian and Pacific Affairs of Senate Foreign Relations Committee, has expressed concern over the actions of a Chinese military vessel that reportedly blocked a US missile cruiser, the USS Cowpens, in international waters, risking the lives and safety of US Navy personnel.
In a letter to Secretary of State John Kerry, Rubio said this incident in December was just the latest display of irresponsible and aggressive Chinese behavior towards American ships and aircraft while in international waters and airspace.
He urged the Administration to take action and raise the issue with the highest levels of the Chinese government.