(GPA) Washington – Today the pentagon announced they have sailed past a set of islands claimed by China in the latest “freedom of navigation” drill since July.

The destroyer USS Decatur passed near the Paracel Islands which the Chinese government claims as Chinese territory. This is the fourth “freedom of navigation” operation through the contested waters this year.

Pentagon spokesman Commander Gary Ross was quoted in a press conference regarding the maneuver saying: “This operation demonstrated that coastal States may not unlawfully restrict the navigation rights, freedoms, and lawful uses of the sea that the United States and all states are entitled to exercise under international law.”

This is the first US operation in the waters since the pro-western decision in a special tribunal in The Hague earlier this year that ruled china had no rightful claim over the area. The Paracel islands are also claimed by both Vietnam and Taiwan.

This newest show of force from the US comes right after Filipino president Rodrigo Duterte visited China on a business and diplomatic mission (the Pentagon claims this is not related to today’s operation.) Duterte spoke of ending the long standing relationship with the United States in favor of a new one with China. What effect this will have on the territorial waters in this area is still unclear seeing as the Philippines have competing claims with Beijing on who some areas belong to.

Commander Ross says this drill is not in favor of any one nation’s territorial claim over the area or any “land features” but that “this operation was about challenging excessive maritime claims.”

China has the largest claims over what areas of the South China Sea belong to them. Washington says Beijing has become increasingly restrictive on movement through the area. The only sure thing is that this will continue to raise tension between the US, their regional allies and China as far as this important theater of operations is concerned.