“We’d like to improve all the nine, especially the islands we are occupying,” Brawner said, referring to the nine features, including reefs and islands, it occupies in the South China Sea.

These include the Second Thomas Shoal, locally known as Ayungin, as well as Thitu Island, the biggest and most strategically important in the South China Sea.

Known locally as Pag-asa, Thitu lies about 480km (300 miles) west of the Philippine province of Palawan.

The military wishes to install a desalination machine on a warship that the Philippines deliberately grounded on Second Thomas Shoal in 1999 to assert its sovereignty claim, Brawner said.

“We are just trying to make it more liveable, more habitable for our soldiers because they really have poor living conditions,” he said.

Brunei, Malaysia, Taiwan and Vietnam all claim sovereignty over areas in the South China Sea, which is a conduit for goods with a value in excess of $3 trillion annually.

However, Beijing claims almost the entire South China Sea and has ignored a 2017 international tribunal ruling that found its assertions were without legal basis.

Recent months have seen Beijing in tense standoffs with the Philippines in the disputed seas.

Chinese ships also blasted a water cannon at Philippine boats.

Beijing seized Scarborough Reef from Manila in 2012 after a months-long standoff.