China has unveiled a monument to mark its construction work in the disputed South China Sea, which has included reclaiming land for artificial islands, the Chinese military’s official newspaper said on Tuesday.

China’s building work has unnerved its neighbors and caused alarm in Washington, especially as much of the construction has been for military facilities like airports.

China has repeatedly defended the work, saying it has every right to build on what it considers inherent Chinese territory and that it is building public facilities, like weather stations and typhoon harbors.

In a brief report, the People’s Liberation Army Daily said the monument was unveiled on Monday on Fiery Cross Reef on the Spratly Islands, where China has built one of its airstrips and other military facilities.

The monument sends a message about China’s determination to protect its territory and maritime rights, the brief report added.

China recently completed extensive military exercises in the South China Sea, where its claims are hotly disputed by Vietnam as well as the Philippines, Malaysia and Brunei. Taiwan also lays claim to most of the sea.

China’s construction of islands and military facilities in the South China Sea, through which some US$3 trillion in trade passes annually, has sparked concern it is seeking to restrict free movement and extend its strategic reach.

The United States has conducted “freedom of navigation patrols” through the South China Sea, stoking tension with China which says it will protect its sovereignty.

- Reuters