The Chinese military is planning to conduct a large-scale landing drill off Hainan Island in the South China Sea in August to simulate the possible seizure of the Taiwanese-held Pratas Island in the future, Chinese sources familiar with the matter have said.

The Chinese People’s Liberation Army is becoming increasingly concerned about the growing U.S. military presence in the South China Sea, and such a drill could escalate tensions. The U.S. Navy said on Thursday it had sailed a guided-missile destroyer through the sensitive Taiwan Strait.

Pratas Island, located in the middle of the route from China’s military base on Hainan Island to the Pacific Ocean, is strategically important for China’s advance into the Pacific Ocean. China’s first domestically built aircraft carrier, the Shandong, was also deployed last December to the base on Hainan, increasing pressure on the Chinese military to capture the islet.