BEIJING, April 25 (Xinhua) -- China's Ministry of National Defense on Monday responded to media reports that six U.S. Air Force planes performed a flight mission in "international airspace" in the vicinity of Huangyan Island in the South China Sea on April 19.

This photo taken on Dec. 11, 2015 shows uniquely beautiful winter scenery of the Zhaoshu Island in the South China Sea. (Xinhua file photo/Zhao Yingquan)

"We have noticed such reports, and it should be pointed out that the U.S. is pushing militarization of the South China Sea in the name of 'Freedom of Navigation,'" the ministry's Information Bureau said in a statement.

China is concerned about and opposed to such actions which threaten the sovereignty and security of countries around the South China Sea and undermine regional peace and stability, it stressed.

Huangyan Island is China's inherent territory and the Chinese military will take all necessary measures to safeguard national sovereignty and security, it added.