China has said that the US warships had illegally entered into the Chinese territorial waters into the South China Sea.

In a statement, the Chinese military's Southern Theatre Command said the USS Curtis Wilbur entered the waters near the Paracel Islands without permission, adding that its ships and planes followed the U.S. vessel and "expelled" it.

The United States, however, has claimed that the Chinese accusations are false. The U.S. Navy's 7th Fleet said the vessel "asserted navigational rights and freedoms" near the Paracel Islands, over which China, Taiwan, and Vietnam all claim sovereignty.

"USS Curtis Wilbur was not 'expelled' from any nation's territory," it said.

"USS Curtis Wilbur conducted this Freedom of Navigation Operation (FONOP) following international law and then continued to conduct normal operations in international waters."

The PLA has, however, said that the US' action undermined the Chinese national sovereignty and territorial integrity.