South Korea expressed regret on Sunday over China‘s recently announced air defense zone that partly overlaps with its territory, prompting concerns for a possible dispute between the neighbors.

A day earlier, China’s defense ministry announced that it has set up an Air Defense Identification Zone over the East China Sea, obligating all aircraft entering the area to report to Chinese authorities and follow their instructions.

Air Defense Identification Zones are set up to distinguish civilian aircraft from military jets in the interest of national security, but no country can claim jurisdiction over them under international law.

“We find it regretful that China‘s air defense zone partly overlaps with our military’s KADIZ (Korean Air Defense Identification Zone) in the area west of Jeju Island,” Seoul‘s Defense Ministry said in a statement, referring to a resort island off South Korea’s southern coast.

A military source here said earlier in the day that the overlapping area is 20 km wide and 115 km long, or about 1.3 times the size of Jeju.

“We will discuss with China the issue so as to prevent its establishment from affecting our national interests,” the ministry said.

Vowing efforts “to promote mutual trust among the countries,” however, the Seoul government said the issue “should not be a factor raises tension in the region.”

The Chinese zone also includes the South Korean-controlled Ieodo, a submerged rock that lies within the two countries‘ overlapping economic zones.

Ieodo, which lies 149 km southwest of Korea’s southernmost island of Marado and closer to South Korea than any other country, is also included in Japan‘s air defense zone but excluded from KADIZ, a ministry official said.

Any aircraft entering an air defense zone without authorization can be subject to interception by fighter jets.

“Our jurisdiction over Ieodo will not be affected by the establishment of the air defense zone either by China or Japan,”

Seoul’s ministry said, vowing “continued discussions” with the neighboring countries. (Yonhap News)