US on 31 January 2014 warned China against any move to declare a new Air Defence Identification Zone (ADIZ) over the South China Sea.This came after the reports of Japanese media that says that China is preparing to announce another defence zone in the area, which are driven by territorial disputes with the neighbouring countries. Marie Harf, the deputy spokeswoman of State Department has said that any such step of China would be seen as a provocative and unilateral act, which could raise tensions and call into serious questions on China over its commitment to diplomatically managing territorial disputes.
On part of Japan, Beijing claims the South China Sea in its entirety although areas are long way from its shoreline. In 2013, China caused a storm when it declared ADIZ above the East China Sea, which included islands at the heart of a sovereignty row with Tokyo. China in December 2013 displayed its aggressive behavior towards the ships and aircrafts of America in international airspace and waters.