U.S. bomber jet’s flight over disputed sea angers China

China’s military went on high alert during the incident and ordered the American bombers to leave the area, Chinese Foreign Ministry spokesman Hong Lei said, according to the state-run Xinhua news agency.

In a statement, the ministry confirmed the strategic bombers had entered the airspace near a man-made island on December 10, accusing the U.S. of deliberately raising tensions in the disputed region.

In response to U.S. pressure to play a bigger role in deterring increasingly assertive Chinese naval activity in the South China Sea and East China Sea, Tokyo is to position a line of anti-ship and anti-aircraft missile batteries along 200 islands stretching 870 miles (1,400km) from the Japanese mainland towards Taiwan.

However, the U.S. has been conducting so-called freedom of navigation exercises through the area over the past few weeks, including sailing one of its naval destroyers within 12 nautical miles of Chinese-controlled territory in the South China Sea in October.

Australia was the second country after the United States to challenge China’s claim to nearly all of the South China Sea which is roiled in tension after China transformed reefs into artificial islands capable of supporting military facilities. Bill Urban as saying in Washington that China had raised its complaints over the flight and the U.S. was investigating. “China has always supported freedom of navigation and we are for creating a code of conduct to ensure smooth navigation in that region”, he said, asking external powers not to meddle in the issue.

He added that the United States, which has yet to confirm how many bombers were involved in the mission, is now looking into the matter.

The US uses pre-planned freedom of navigation operations to assert its rights to “innocent passage” in other country’s territorial waters. China says a US bomber got too close to one of the islands.

This isn’t the only recent potential cause of trouble in the South China Sea.

US Representative Sheila Jackson Lee and Representative Mike Bishop shared similar views and lauded Taiwan’s efforts to promote peace and stability in the South China Sea. At the time, China referred to the destroyer sail-by as an “extremely irresponsible” move.

Concern over China’s maritime and aerial presence in the East China Sea – including around the disputed Senkaku island chain – mirrors unease over Beijing’s construction of manmade island bases in the contested Spratly archipelago in the South China Sea.

On Wednesday, Beijing filed a formal diplomatic complaint and its Foreign Ministry said it would take “necessary measures, including the imposition of sanctions against companies participating in the arms sale to Taiwan”.

Beijing insists it has sovereignty over virtually all of the resource-rich South China Sea, conflicting with the various claims of Vietnam, Malaysia, the Philippines, Taiwan and Brunei.