China has accused the United States of violating its sovereignty after a US missile destroyer sailed near Huangyan Island, also known as Scarborough Shoal, on January 17, in the South China Sea.

The USS Hopper sailed within 12 nautical miles of the shoal, according to a report on Voice of America.

A statement from China’s Defense Ministry said in a Chinese frigate “immediately took actions to identify and verify the US ship and drove it away by warning.”

Sovereignty over Huangyan Island is a matter which is in dispute between China and the Philippines. The Philippines claim China seized Huangyan in 2012. China is also in territorial disputes with Vietnam, Malaysia, Taiwan, and Brunei over areas of the South China Sea. The Philippines won legal claims against China before a United Nations arbitration panel in 2016, a determination which China has rejected.

China has been building artificial islands to house military bases in the area, part of a larger strategy to claim hegemony over the western part of the Pacific Ocean.

Thousands of cargo ships transit the waters of the South China Sea every day, connecting markets and goods in East Asia with the Middle East and Europe. An estimated $5.3 trillion in annual trade, $1.2 trillion of which begins or ends at US ports, and one-third of the world’s liquefied natural gas passes through the South China Sea on a yearly basis.

The US has no territorial claims in the South China Sea but has said it is concerned China is trying to militarize what should be free and open international waters. The US Navy regularly sails through the area to assert freedom of navigation.