Mischief and Subi reefs are among the artificial islands China has used to expand its offensive capabilities in the region.

The United States, Japan and the Philippines have staged joint naval drills to boost crisis readiness off a disputed South China Sea shoal as a Chinese military ship kept watch from a distance.

China's military said it had conducted a patrol in the South China Sea on Friday, the day U.S. Defense Secretary Pete Hegseth reaffirmed Washington's commitment to Manila, which disputes some of Beijing's claims in the waterway.