A United States Navy aircraft carrier group began “routine” patrols in the South China Sea on Sunday. In a statement, the navy said the USS Carl Vinson group was engaging in the operations after having completed exercises off Hawaii and Guam to “maintain and improve their readiness and develop cohesion as a strike group”, AFP reported.

“We are looking forward to demonstrating those capabilities,” the statement said, adding that Washington was looking forward to “building upon existing strong relationships with allies, partners and friends in the Indo-Asia-Pacific region”. The navy said the USS Carl Vinson has been deployed to the South China Sea 16 times in the past 35 years.

On Wednesday, China said that it knew of the aircraft carrier’s group patrol and that ships and aircraft were allowed to operate in the area as per international law, CNN reported. However, foreign ministry spokesperson Geng Shuang said Beijing “firmly opposes any country’s attempt to undermine China’s sovereignty and security in the name of freedom of navigation and overflight”.

In July 2016, an international tribunal in The Hague had ruled in favour of the Philippines and said Beijing had no legal basis to claim “historic rights” over the South China Sea. The Permanent Court of Arbitration accused China of breaching the sovereign rights of the Philippines by exploring resources near the Reed Bank. However, the Chinese government dubbed the verdict “ill-founded”. Beijing has also said that its “territorial sovereignty and marine rights” in the seas would not be affected by the verdict. Washington has so far not officially taken any side in the territorial disputes.